Proceedings of the Tomsk Technological Institute

of Emperor Nicholas II

Vol. 6. 1907. No. 3.

M. I. Yuzhakov

Report on an Overseas Business Trip

I–II, 1–45.

REPORT

ON AN OVERSEAS BUSINESS TRIP

of the lecturer of the Tomsk Technological Institute of Emperor Nicholas II

M. I. Yuzhakov.

Having finished my classes at the institute on November 1, I left Tomsk on November 5 and arrived in Petersburg on November 15. Obtaining a foreign passport and the trouble connected with receiving the travel funds, which were already on their way to Tomsk, took me no little time; having received the documents and money on November 27, I left for Berlin on the 29th, where I arrived on December 15, new style, that is, precisely at the Christmas holidays. I did not find it possible to enroll for lectures after having missed more than two months, and, in order to make better use of the time allotted to me, I decided to occupy myself with the literature on gas engines—especially since my intention was assisted by the kindness of the secretary of the Charlottenburg Polytechnic, who permitted me to use the library.

While waiting for the summer semester, I considered it necessary, together with my literary studies, to inspect several factories and works, and with this aim I went to Hanover, in order to examine there the Polytechnic and the very well-known factory of Br. Körting, with a description of which I shall begin the present report.

The factory of Br. Körting is located on the southwestern side of Hanover—Linden. Thanks to the courtesy of the factory’s designer, Mr. Trimpler, I had the opportunity to visit this factory twice. In view of the fact that visitors are admitted to the factory only once a day (before lunch or after lunch), I decided to devote the greater part of the time to the gas-engine assembly shop, thus directing my chief attention exclusively to the aspect that interested me. The factory is served by gas engines. In the assembly shop there are two two-stroke Körting engines of 160 HP each. All

the engines operate on generator gas (Dowson gas), whose composition, according to factory data, is as follows:

The gas is obtained from four generators installed in a separate room, whose total capacity is about 1800 horsepower.

The factory chiefly builds large two-stroke gas engines, operating both on Dowson gas and on blast-furnace gas. In the last three years the factory has produced such engines with a total capacity of 90,000 HP.

The Koerting gas engine resembles a steam engine. In it, just as in a steam engine, the inlet valves are located at the ends of the cylinder; the exhaust port, however, is placed in the middle of the cylinder, which is closed at both ends by covers. Koerting’s two-stroke engines are double-acting.

When the piston moves, it closes and opens the exhaust port of the cylinder by itself. The combustible mixture is fed into the engine under a pressure of about 0.6 atmosphere by special auxiliary double-acting pumps. There are two pumps: one of them supplies air, and the other gas. When the piston moves to the right under the pressure of the gases formed as a result of combustion of the mixture in the left-hand part of the cylinder, compression takes place in the right-hand part of the cylinder; at the same time the piston opens the exhaust port, so that the gases from the left-hand part of the cylinder can escape into the atmosphere; instead of the spent gases, pure air is admitted into the left-hand part of the cylinder, which, as it were, flushes this part of the cylinder of the burnt gases, and then a mixture of gas and air is admitted, which, on the return movement of the piston to the left, is compressed and at dead center ignites. On the other side of the piston the same thing occurs, but in the reverse order. As we see, the Koerting gas engine, like a steam engine, is double-acting. The regulation of the engine’s stroke is carried out in the following manner: when the load decreases, the gas pump begins later to deliver gas to the working cylinder and in a smaller quantity. Thus the engine works with a variable quantity of gas in the mixture, or in the charge. This kind of regulation cannot be considered rational, for the following reason: already

at \(1/4\) of the normal load, the gas mixture may turn out to be so poor that it may fail to explode and the machine will misfire; in other words, the regulation is reduced to a system of regulation by misfires, with the sole difference that here, with a non-exploding charge, an unnecessary loss of gas occurs. Ignition of the charge is effected by magnetic inductors, mounted two on each side of the working cylinder. All four igniters are brought into action by a special countershaft, which receives its motion by means of toothed wheels from the main shaft of the machine. The machine is started by compressed air at a pressure of about 10 atmospheres. A special movable shaft actuates a sliding and extendable distributing slide valve, as in steam engines with throttle distribution; this slide valve admits compressed air to the right and to the left of the cylinder. Usually two or three fillings of the cylinder are sufficient, after which the machine can already do work by itself. The cylinder, the valves, and even the piston are cooled by circulating water through a hollow rod.

At this same works I had occasion to become acquainted with Mr. Trinkler’s engine. The engine has already been built, and Mr. Trinkler is testing it, improving certain structural parts, and, it may be hoped, in a short time this engine will be released onto the market. The engine is four-stroke. The principal essential part of the engine, by virtue of which it is chiefly distinguished from others similar to it, is the injection apparatus, which is patented in all civilized countries of the world. A diagram of this apparatus is shown in the accompanying sketch and has the following arrangement. In the middle of the cylinder cover there is a nozzle for admitting a liquid combustible material (petroleum or kerosene); above it is placed the distinctive feature of Trinkler’s engine—a special small cylinder with a small piston, which automatically (owing to the difference in pressures, as will be said below) sprays petroleum or kerosene through the nozzle into the working cylinder of the engine. Almost no work is expended on moving this small piston—this is one of the chief advantages. During the first stroke of the piston of the working cylinder to the right, air is drawn in, and at the same time a certain quantity of kerosene or petroleum is supplied through the channel \((k)\) and enters the depression \(f\), made in the form of a small cup of the nozzle (see Fig. 1). The piston of the small distributing cylinder is always in the right-hand position, as shown in Fig. 1. In this position it is held by the rod (latch) \(a\), fixed at the point \(A\).

During the return stroke of the working piston, i.e. during the leftward stroke, the air in the cylinder is compressed to 30 atm. This compression, by means of the channels \(h\), which connect the working cylinder with the distributing cylinder \(P\), is transmitted to the latter. If we denote the area of the piston of the distributing cylinder by \(F\), and the area of its rod by \(f\), then the pressure on this piston from the right will be equal to \(30F\), while the pressure on the same piston from the left will be \((F-f)\cdot 30\)—a quantity smaller than \(30F\). Under the force of this difference of pressures, the piston would naturally move to the left, if it were not held in its initial position by the latch \((a)\). At the moment when the piston of the working cylinder has almost approached the left dead point, the cam \(C\), striking and deflecting the latch \(a\), allows the piston, under the action of the difference of pressures, to move rapidly to the extreme left position. During this movement to the left, the piston \(F\) compresses the air behind it to 50–60 atm. The air compressed in this way in the little cylinder \(P\) flows at high speed through the small channel \(B\) (see Fig. 1) and, carrying with it the oil (or kerosene) located in the cup \(f^1\) of the injector, injects it instantaneously into the working cylinder, precisely at the time when the working piston is at the dead point; the injected oil, owing to the high temperature produced by the compression of the air, ignites and produces an explosion. Such is the idea of Trinkler’s engine. The motion of the engine is fairly smooth and uniform. The operation of the engine may be judged from the diagram appended herewith (see the following page). The engine is intended to run on petroleum, although the trials are so far

on kerosene. The consumption of kerosene is 215–216 grams per horsepower-hour for a 14-horsepower machine (number of revolutions 200). Owing to the fact that in the Trinkler engine almost no work is expended on the pump, it is to be expected that the mechanical efficiency of this engine will be higher than in the Diesel engine.

On the same factory ship, Br. Kerting, I happened to see a remarkably small, valveless two-stroke engine, which runs either on gasoline (specific gravity 0.68–0.70), or on alcohol, or on a mixture of alcohol and benzine (80% alcohol, 20% benzine), or on kerosene, petroleum, solar oil, etc. In my presence this motor ran on various fuels, the fuel material being changed without stopping the motor. This engine is also currently undergoing tests. It makes 1200 revolutions per minute and develops 12 horsepower. The diameter of the cylinder is about 100 mm, the stroke of the piston 100–120 mm. The engine is vertical and has the following arrangement. The engine consists of a cylinder A, in which there is a piston a, connected by means of a rod to the crankshaft of the motor. The crankshaft is located in an enclosed space, as is always done in two-stroke motors. When the piston moves upward, a rarefied space is formed above the piston. As soon as piston a (see Fig. 3), during its upward motion, opens port C, through the latter a thundering mixture enters the cylinder. But before port C is fully opened, the piston, by means of a recess f made in it, connects ports d and g, owing to which atmospheric air passes through d, f, g and fills channel h. During the return motion, as a result of the flash that has occurred in the upper part of the cylinder, the piston covers with its body ports C, g, and d, and almost at the lower dead point opens the exhaust passage n, through which the spent gases pass out into the atmosphere. With the further downward motion the piston opens port g, through which there enters into the cylinder, situated in channel h, clean air, which, moving in the direction of the arrow,

Indicator diagram of the Trinkler engine.
Load 14.6 horsepower; number of revolutions 215; spring—1 mm.

Fig. 2.

washes out the remaining burnt gases in the cylinder; then, through this same channel \(h\), the mixture enters from the lower part of the cylinder. During the upward motion of the piston, the mixture located in the upper part of the cylinder is compressed and is ignited by means of an electric spark. The clean atmospheric air in the small channel \(h\), besides washing the interior of the cylinder, has another very important function: it prevents the incoming fresh mixture from coming into contact with the remaining spent and possibly still hot gases, thereby preventing premature flashes. The motor is regulated by a throttle valve, and the number of revolutions may vary from 0 to 1200 per minute.

Fig. 3.

I made use of my stay in Hanover to inspect the mechanical laboratory of the Hanover Polytechnic, which I succeeded in doing thanks to the kindness of Prof. Frese.

The mechanical laboratory of the Hanover Polytechnic is located on the lower floor of the Polytechnic building. The laboratory course is two years long. Work is conducted in groups. In the first year the students engage in testing various materials for tension, bending, and compression. For this purpose there are three machines: a Schenck machine from Darmstadt, a Tarnogrodsky machine in Essen, and a Lehmann machine in Dresden. In the second year the students investigate the steam engine, gas engines, and the steam turbine; for this purpose the laboratory has installed: 1) an 8-horsepower Deutz gas engine, 2) two atmospheric gas engines of the same factory, each of \(1/3\) horsepower, 3) a 3-horsepower Hornsby kerosene engine, 4) a 40-horsepower triple-expansion steam engine, 5) a Rider machine, driven by hot air—1 horsepower, and 6) a de Laval steam turbine*).

The eight-horsepower gas engine is of a rather old design (with a crosshead). Ignition is by means of an ignition tube, also one that has almost outlived its day; until now I had only happened to see an ignition tube in an engine of the Banki system, and even there it exists—

) Z. d. V. d. I.* 1900. Article by Frese.

is there only because it is inconvenient to use the magneto-electric ignition now adopted almost everywhere, since a certain quantity of water is injected into the cylinder in order to achieve higher preliminary compression (Banky patent). The engine is regulated by changing the composition of the explosive mixture, i.e. by regulating the amount of gas contained in the mixture. For measuring the consumption of gas and air, carefully calibrated Elster-system gas meters in Berlin are used. In order to balance the resistance offered by the gas meters to the air, the latter is supplied with a slight excess pressure obtained by means of a small hand fan. During the experiments the pressure and temperature of the gas, the temperature of the air, and the temperature of the entering and leaving circulating water are measured. The average temperature of the exhaust gases is measured by a Le Chatelier pyrometer inserted into the branch pipe. The calorific value of the gases is measured with a Junker calorimeter, and the shaft work by a dynamometer and Deutz brake. The steam engine is of the horizontal type, made by the K noevenhagel works, with three cylinders whose diameters are 20, 30, and 45 cm. The axes of the high- and medium-pressure cylinders are arranged on one straight line. The axis of the low-pressure cylinder is on a straight line parallel to the first. The cranks are fixed on the main shaft at right angles. Steam distribution in the high- and medium-pressure cylinders is by a double Meyer-Rider slide valve, while in the low-pressure cylinder valves serve for admitting steam, and taps for exhausting it. The machine can operate either with triple expansion, or as a compound, or as a Woolf machine (tandem). In the second case (compound) the rod of the high-pressure cylinder is disconnected and the steam is admitted directly into the medium-pressure cylinder. In the third case (tandem), the steam from the medium-pressure cylinder is discharged into the condenser, and the piston of the low-pressure cylinder moves idle. All cylinders and their covers are provided with steam jackets, but they can also operate without them. The number of revolutions of the machine is 120. The machine is provided with a Deng dynamometer having the following arrangement (see the sketch in Fig. 4). A brake band b is placed on the brake pulley a, which rotates in the direction of the arrow. One end of this band is fastened to the lever c, which at one end bears against the shaft of the brake pulley and at the other is suspended at the point m′ by means of the rod l′ from the balance beam h. The other end of the brake band is tightened by the lever f, the left end of which (see the sketch) can rotate freely about the point g, while the right end is suspended by means of the rod l″ from the balance beam e. The distances of the points of suspension m′ and m″ from the axis of the pulley are equal. (In the drawing these distances are shown as different--

personal for clarity). The yoke \(h\) carries the load \(p'\), placed on the handle \(i\), and the yoke \(e\) carries the load \(p''\), placed on the handle \(k\). The brake’s own weight is balanced by the load \(q\). The loads \(q'\) and \(q''\) are placed on the pans \(\omega'\) and \(\omega''\), attached to the yokes \(h\) and \(e\). A special feature of this brake is the circumstance that, when the levers \(f\) and \(c\) (and, consequently, the yoke) are deflected from the horizontal position, the relation between the braking force and the difference of the loads \(q' - q''\) does not change.

Fig. 4.

While in Berlin, I visited factories from time to time; thus I inspected: a department of the Deutz factory, Daimler’s engine works in Marienfelde, the Borsig factory (Tegel), and the factories of Julius Pintsch in Berlin and Fürstenwalde. I shall postpone the description of the engines of the Deutz factory until my visit to the factory in Deutz (Cologne).

The Daimler factory (a joint-stock company) builds alcohol engines—stationary and locomobile—of its own system, differing little from other already known systems. The engines are of the horizontal type, four-stroke, and are built from 2 to 35 horsepower, with the number of revolutions shown in the table; in the same table the prices of the engines are also shown, in German marks.

The consumption of alcohol in these engines per horsepower-hour extends from 0.5–0.6 liter, depending on the size of the engine. A distinctive feature of Daimler engines is the low consumption

cooling water, namely, according to the plant’s assurance, from \(3/4\) to 1 liter per hour per horsepower. Ignition is effected by a magneto-electric igniter. The engines are distinguished by their compact arrangement and sound design.

Then, as I have already said, I inspected the Julius Pintsch factories in Berlin and in Fürstenwalde on the Spree.

The Berlin factory of Julius Pintsch, having about 1,000 workers, is engaged exclusively in the manufacture of burners and lamps for all the railways of Germany. At this factory the principle of mass production has been applied in its full breadth, greatly reducing the cost of the manufactured articles.

The Julius Pintsch plant in Fürstenwalde is engaged in the manufacture of mines, floating beacons, and also, in large numbers, generators for engines running on Dowson gas. The plant does not build engines. The excellently organized welding of iron at the plant attracts attention. I had occasion to see floating beacons of enormous size—without a single rivet—all welded. Welding has achieved such brilliant results thanks to the use, for this purpose, of the extremely convenient “water” gas. “Water” gas is obtained by passing steam through an incandescent layer of anthracite or coke; in this process the steam decomposes into hydrogen and oxygen.

The carbon of the coal burns at the expense of the oxygen released from the steam into carbon monoxide at a high temperature, and at a less high temperature—into carbon dioxide. The course of this process may be expressed by the following reactions:

\[ \mathrm{C} + 2\mathrm{H}_2\mathrm{O} = \mathrm{CO}_2 + 2\mathrm{H}_2 \]

Or:

\[ \mathrm{C} + \mathrm{H}_2\mathrm{O} = \mathrm{CO} + \mathrm{H}_2 \]

In the first case there is obtained (with combustion to \(\mathrm{CO}_2\)) a mixture of carbon dioxide with hydrogen, the specific gravity of this mixture being 0.55, and the mixture contains 33.3 percent by volume of carbon dioxide and 66.7% hydrogen. In the second case there is a mixture of specific gravity 0.52 with a percentage content of 50% \(\mathrm{CO}_2\) and 50% H. In the process of formation of “water” gas both of these cases occur.

The Julius Pintsch plant is served by three two-stroke gas engines of the O. Deutz works, of which two are 150 P.S. each and one is 300 horsepower; the engines run on producer gas (suction principle) and drive dynamos. The transmission is electrical. The current is from the main central station.

Then I inspected the factories in Vienna: Langen und Wolf, Warchalowski und Seidler, Polke, Em. Plewa, and Blaschke, to the description of which I shall now turn.

The Langen and Wolf factory (Vienna X, Laxenburgerstr. 53)—one of the old firms—has existed for 32 years and produces various kinds of motors: alcohol, gasoline, kerosene, engines operating on producer gas and illuminating gas, alcohol and gasoline locomobiles and locomotives (at the international exhibition in Vienna such a locomotive ran on alcohol and hauled 10–12 small cars), as well as regulators of various systems, namely: spring regulators, those of Steinl, Stumpf, and others. The engines produced by the factory are of the Otto-Deutz system (the factory has acquired the right to manufacture these engines), with only minor design modifications. The engines, as is known, are horizontal, four-stroke, with magneto-electric ignition. The factory produces a large number of gas engines in connection with generators. According to the factory’s data, it appears that by July 1, 1903, 1,163 such engines had been produced, with a total power of 36,188 horsepower. In the Technologisches Gewerbemuseum in Vienna, in April 1902, tests were carried out on a 6-horsepower Otto engine built by the Langen and Wolf factory. During the test the engine was made to operate with four different fuels: gasoline, petroleum, benzol, and illuminating gas. The test data are given in the following table:

Knowing that 100 kg of gasoline (specific gravity 0.700–0.705) cost 24 crowns, 100 kg of petroleum (specific gravity 0.720–0.740)—16 crowns, 100 kg of benzol (specific gravity 0.880)—20 crowns, and 1 cubic meter of illuminating gas in Vienna costs 0.14 crown, it is easy to calculate, using the table, that 1 horsepower-hour costs:

As we see, it is most advantageous to work with petroleum, namely: 1 effective horsepower-hour costs only 4.56 Heller, or 1.78 kopecks. Of course, such an insignificant cost of effective power per hour is valid for Austria, where its own petroleum is produced (in Galicia). In Germany, for example, it is more advantageous to work with alcohol than with petroleum, since the cost of denatured alcohol in Germany is 18 marks per 100 kg, while petroleum in Germany costs 24 marks per 100 kg. In the Technologisches Gewerbemuseum, in December 1902, an alcohol engine of the Langen & Wolf works was also tested. The engine was an eight-horsepower one. Load: 11.9 horsepower; number of revolutions: 210. Fuel consumption was 0.375 kg per horsepower-hour. If this engine were to operate in Austria, the cost of a horsepower-hour would be 14.25 Heller, or 12.1125 Pfennig. If the same engine were to operate in Germany, then the cost of power per hour would be only 6.75 Pfennig, i.e. almost twice as cheap. When operating on petroleum, as we have seen, the opposite is true. Hence it is clear that in Germany one should expect the development of the manufacture of alcohol engines, which is also confirmed by the existence in Germany of the enormous alcohol-engine factory in Oberursel; in Austria, on the other hand, the development of gasoline engines (petroleum—heavy gasoline).

At present the price of petroleum in Vienna is 14 crowns per 100 kilo. The Langen & Wolf factory is served by two 30-horsepower motors running on producer gas and one 12-horsepower gasoline motor; at present a 100-horsepower motor, running on producer gas, is being installed at the factory for electric lighting and transmission. The 30-horsepower engine operating at the factory consumes per horsepower-hour 0.45 kilo of Belgian anthracite, to which must be added another 10% for kindling (blast) to the quantity consumed in 10–12 working hours. The analysis of the producer gases obtained, according to the factory data, is as follows:

The calorific value of such gas is about 1100–1350 cal. per cubic meter; it burns with a bluish flame, and from 1 kg of anthracite or coke one obtains from 4 to 4.8 cubic meters of gas. The oil consumption for

in horsepower-hours in motors manufactured by the Langen & Wolf factory, with a capacity of up to 30 PS—2.4 grams; in 100-horsepower motors the consumption of oil is 1.6 grams per horsepower-hour; in a 200-horsepower motor—1 gram. About 40–50 liters of cooling water are consumed per horsepower-hour.

The Warchalowski and Seidler factory (Vienna, III Paulushgasse, 3) builds motors running on petroleum, from 1 to 35 horsepower, and motors running on generator gas up to 100 horsepower. The generators are obtained from Julius Pintsch (the factory itself does not build generators), who guarantees a consumption of 0.5 kilo of Belgian anthracite per horsepower-hour. The engines manufactured by the factory run on alcohol or on petroleum (specific gravity 0.76). The engines are distinguished by simplicity of construction; they are horizontal, 4-stroke. Ignition is magneto-electric. Instead of a screw transmission from the main shaft to the distributor shaft, a cylindrical transmission is arranged, which considerably cheapens production, especially if one takes into account the simplicity of construction that distinguishes the motors of the Warchalowski and Seidler factory.

The consumption of petroleum per horsepower-hour is from 0.3 to 0.45 kg, depending on the size of the motor. The consumption of cooling water is 20–35 liters for small motors and 15–25 liters for large motors per horsepower-hour. Approximately 125 kilos of oil are consumed in a year for a 10–12 horsepower motor (with 10 hours of operation per day). The motors of this factory allow a significant overload; thus an 8-horsepower motor working at the factory operates at 12 horsepower. I attach an indicator diagram of a 10-horsepower motor (Fig. 5). Load: 71 amp × 85 volt. Number of revolutions: 240. Spring: \(2^{1}/_{2}\) mm.

Fig. 5.

The Warchalowski und Seidler engines were tested at the Technologisches Gewerbemuseum. For the test, engines of 10 and 25 horsepower, running on petroleum, were taken. The results are as follows: the 10-horsepower engine, at idle, made 184 revolutions, the number of flashes per minute being 18; the engine was loaded; load = 12.92 P.S. Number of revolutions: 173; number of skips: 12. Consumption: 0.35 kg of petroleum (specific gravity 0.76) per horsepower-hour. The 25-horsepower engine, at idle, made 154 revolutions with 14 ignitions per minute; it was loaded to 26.6 horsepower, whereby

the number of revolutions decreased to 145, and the number of misfires was 18. The consumption was 0.35 kg of petrol per hour per effective horsepower.

The factory of J. Polke (Wien V/2, Kohlgasse 24–28) manufactures engines running on petrol and producer gas, with a capacity from 1 to 100 horsepower. The motors are horizontal, four-stroke.

The number of revolutions is from 140 to 180, depending on the size of the motor. The petrol consumption per hour per effective horsepower is 260 g for small motors, and considerably less for large ones. The ignition in all motors is electric. At the factory a 25-horsepower motor has been installed, running on producer gas 10 hours daily, the average consumption being 80 kg of Belgian anthracite per day, which gives about 0.5 kg per horsepower-hour. The same anthracite consumption was shown by tests of the Technologisches Museum in Vienna, where Polke engines were tested. A 20-horsepower Polke engine*) was tested, running on Dowson gas, the maximum load being determined at 24.7 horsepower. At the start of the tests the generator was cold, and after only 25 minutes it was possible to set the motor in motion; for four minutes the motor ran without load, and then a load of 22.4 horsepower was applied. Loaded in this way, the motor ran for 4 hours 20 minutes, made on average 160 revolutions per minute (fluctuations 159–161), while the anthracite consumption (together with kindling) over this entire time proved equal to 49 kg, which corresponds to a consumption of about 0.5 kg per effective horsepower-hour. Next, the consumption of cooling water, the water consumption in the scrubber, and the water consumption in the evaporator were determined, namely:

Water consumption for cooling the motor:

Water consumption in the scrubber:

Water consumption in the evaporator:

*) Cylinder diameter—345 mm, piston stroke 460 mm.

Thus the total water consumption per hour will amount to 532 liters, which is about 24 liters per 1 horsepower per hour.

The results of the tests, as we see, are extremely favorable. Polke motors are distinguished by an original transmission from the main shaft to the mixing valve (Polke patent), as well as by smooth and quiet running and good design. I attach here an indicator diagram taken by me at the works from a 4-horsepower engine operating on illuminating gas (Fig. 6). The load was 5.6 horsepower. Number of revolutions—160. Spring 2 mm—1 atm.

Fig. 6

The factory produces more than 100 machines per year.

The motors of the Polke factory also run on alcohol. A 4-horsepower motor was tested at the Technologisches Gewerbe-Museum. The results of the test were as follows: maximum load 5.11 P.S. At no load it made 184 revolutions with 18 ignitions per minute. At maximum load (5.11 P.S.) the number of revolutions decreased to 173, the number of misfires was 12. The alcohol consumption was determined as 0.508 liters per hour per horsepower. The results, as we see, are also quite favorable.

The Emil Plewa factory (Wien. XVII. Wattgasse 78--80) manufactures steam motors, explosive and gas engines, hoisting mechanisms, etc. The steam motors (Radinger) are made from 2 to 35 P.S.; moreover, from 2 to 6 horsepower vertical motors are built, and from 10 to 35—horizontal ones. A view of a steam motor with a cutaway of part of the boiler is shown in Fig. (7) (see the following page). The principal dimensions of these motors, such as cylinder diameter, piston stroke, heating surface, as well as the number of revolutions and the cost of the motor in Austrian crowns, are shown in the table. The factory produces from 20 to 25 steam motors of various power per year, including 50-horsepower, two-cylinder Compound systems.

TABLE

of the principal dimensions of steam motors of the Emil Plewa factory.

Fig. 7.

The gasoline (petroleum) and gas engines produced by the factory are distinguished by simplicity of design and ease of starting while running. The engines are horizontal, four-stroke. Ignition is by electric magneto, although small engines are also made with an ignition tube. Gasoline consumption is 0.4–0.45 kg per horsepower-hour; gas consumption is 0.55—0.75 cubic meters, depending on the size of the engine. The locomobiles produced by the E. Plewa factory are ordinary stationary, only slightly modified machines mounted on a carriage; on this same carriage are located the cooler and the reservoir for the fuel material.

Next I inspected the Blaschke factory (Wien, V. Romperstorfferstr., 46). This is a small factory, more of a workshop, in which gasoline and alcohol motors are assembled. Nevertheless, the motors are well

are constructed and are distinguished by the simplicity and symmetry of their component parts. Motors with one (usually) flywheel operate on the Otto principle; ignition is magneto-electric. The consumption per horsepower-hour at full load is from 0.4 to 0.45 kg of gasoline or alcohol. For larger motors the consumption decreases to 0.3 kg per horsepower-hour. At the International Alcohol Exhibition in Vienna a 10-horsepower Blaschke motor, operating on alcohol, was exhibited. The number of revolutions was 180. Consumption: 1/2 liter per hour per 1 PS.

I shall now proceed to a description of the motors that were at the International Alcohol Exhibition in Vienna. The following firms were represented by exhibits at the exhibition: Langen und Wolf, Warchalowski und Seidler, Polke, E. Plewa, Blaschke, Ganz u. C^0, A. G. Motoren-Fabrik Oberursel, Climax, Dürr, Christoph, Deutz, and Daymler.

The Langen u. Wolf factory exhibited five motors operating on alcohol and gasoline, of 1, 2, 4, 6, and 30 horsepower. The 30-horsepower engine, distinguished by its new and original design, attracted general attention. The number of revolutions of the engine was 180; consumption was 40 decaliters of alcohol or 28 decaliters of gasoline. In general (in more detail) I have already spoken about the engines of the Langen and Wolf factory when describing the factory (see above).

Warchalowski u. Seidler exhibited two engines, of 6 and 3 horsepower; the firm J. Polke exhibited four motors: of 1, 2, 4, and 8 horsepower, and one locomobile engine of 6 horsepower. Only the 8-horsepower engine was in operation; it made 140 revolutions and consumed 1/2 liter of alcohol per horsepower-hour.

E. Plewa exhibited one ten-horsepower motor, operating on alcohol or petroleum; it consumed 33 decaliters of the former and 55 decaliters of the latter per horsepower-hour. The engine made 180 revolutions. In addition to the motor, a four-horsepower locomobile engine was exhibited, making 220 revolutions. The Blaschke factory exhibited, as I have already said, one ten-horsepower engine, consuming 1/2 liter of alcohol per horsepower-hour. I have already spoken in more detail about all the engines listed when describing the corresponding factories.

The firm Ganz & Comp. (Budapest) exhibited, in a separately built room, a 25-horsepower engine of the Banki system. The number of revolutions was 220. The peculiarity of this system is the fact that, in addition to fuel, water is injected into the working cylinder; by absorbing heat for its evaporation, it makes it possible to increase compression without fearing premature explosions. Banki engines are vertical and are built by the factory from 5 to 50 horsepower. In 1899 Prof. E. Meyer undertook a series of experiments with the engine

Bánki, which continued from September 25 to 28*). The experiments were carried out at the Ganz & Comp. factory in Budapest with a 20-horsepower engine. The engine ran on gasoline, the specific gravity of which was taken, as the mean of three tests, to be 0,700 kg/liter at \(22^\circ\) C. The calorific value of the gasoline, determined by means of Junkers’ calorimeter, was taken, as the mean of two determinations, to be 10290 WE/kg. The lamp heating the ignition tube consumed 0,19 kg of gasoline per hour. The dimensions of the engine were: cylinder diameter 250,3 mm, piston stroke 400 mm. The results of the tests are shown in the following table.

Table I.

From this table of test data one sees a very important property of the Bánki engine, namely: as the load decreases, the consumption of gasoline per 1 horsepower-hour increases only very slowly. Thus, at half load the consumption of gasoline per one effective horsepower-hour is less than 300 g, and at one-quarter load it is less than 400 g. From the same table we see that the consumption of water injected into the cylinder at full load per 1 effective horsepower-hour is equal to \(\frac{32,6}{25,2} \simeq 1,3\) liters.

The mean indicated pressure is greater than in Diesel’s engine, which is easy to calculate. Indeed, denoting by \(\eta\) the mechanical efficiency of the engine, by \(p_i\) the mean indi-

*) Z. V. D. J. 1900.

indicator pressure, \(D\)—the diameter of the cylinder in cm, \(S\)—the piston stroke in meters, and by \(a\)—the number of explosions in 1 minute, we have:

\[ N_e=\frac{\eta\cdot p_i\cdot \frac{\pi D^2}{4}\cdot S\cdot a}{60\cdot 75}. \]

Whence, taking \(\eta=0.85\), we obtain:

\[ p_i=\frac{60\,75\,25.22}{0.85\,\pi\,\frac{25.03^2}{4}\,0.4\,89.8} =7.6\ \frac{\mathrm{kg}}{\mathrm{qcm}^2} \]

Professor Edmund Jonas (Budapest) and the director of the Technological Museum in Budapest repeated Meyer’s experiments. The gasoline used by them had a specific gravity of \(0.730\ \mathrm{kg/lit}\) and a calorific capacity of \(10180\ \mathrm{WE/kg}\). The results of the experiments are shown in Table II. In the table, the gasoline consumption per 1 effective horsepower per hour is shown, excluding the consumption of gasoline for the burner.

Table II.

From these experiments one also sees the insignificance of the increase in hot material falling per 1 horsepower per hour, in comparison with the decrease in load. If, using the data of Table II, we calculate the average indicator pressure (for the 1st test), then we obtain:

\[ p_i=\frac{26.4\cdot 60\cdot 75}{0.85\,\pi\,\frac{25.03^2}{4}\,0.4\,91.4} =6.6\ \mathrm{kg.}\ \text{per sq. cm.} \]

The year before last, Prof. Schimanek proved that Banki’s alcohol motor works still more economically than on gasoline. The results of these interesting experiments are placed in the following Table III.

The alcohol consumed had a specific gravity of 0.906 at \(18.2^\circ\mathrm{C}\). The calorific capacity of the alcohol was determined by Junkers’ calorimeter to be equal to \(5370\ \mathrm{WE}\).

Table III.

Considering the data of the last table, it is easy to observe that the motor being tested works somewhat more economically on alcohol than on gasoline. Indeed, when working on gasoline, 2490 WE are expended per 1 PSe per hour, whereas for the same amount, when working on alcohol, 2090 WE (2088,93) are expended. This may be explained by the fact that the motor, when working on alcohol, with the same compression, requires less injection of water (see Tables III and I) than when working on gasoline; an increase in the quantity of injected water worsens the thermal efficiency of the circular process.

In order to judge the operation of this motor, I append two copies of diagrams (see Figs. 8 and 9). The first is the diagram of a 16-horsepower motor, taken at full load; the second is that of a 3-horsepower Banki motor, taken at a load of 3,8 PS.

Fig. 8.

As is evident from the diagrams, the motor operates with a fairly high preliminary compression, which is achieved thanks to the injection of water into the working cylinder of the engine. The Banki motor also operates on gas. Prof. Chimanecsk (Budapest) likewise carried out a series of experiments with the Banki motor, making it operate on gas. The results of the tests may be seen from the following Table IV.

Fig. 9.

Table IV.

The exhibited 25-horsepower engine is distinguished by the solidity and simplicity of its construction, has an even and smooth running action, and all parts of the engine are easily accessible for inspection.

Motoren—Fabrik Oberursel (A. G.) exhibited eight alcohol engines: two six-horsepower engines (280 revolutions), one two-horsepower engine (300 revolutions), one four-horsepower engine (290 revolutions), and 4 locomotive engines of 4, 6, 10, and 12 horsepower. These engines consume 0.36–0.4 kg of alcohol per horsepower per hour. A section of the vertical alcohol engine (gnome) is shown in the accompanying drawing (see Fig. 10). The engine is four-stroke. The ignition is magneto-electric. The inlet valve J opens by itself, owing to rarefaction in the cylinder during the first stroke of the piston. The exhaust valve A is opened at every revolution of the main shaft of the engine by means of an eccentric. The engine is regulated by the exhaust valve. The engine, as we see, is distinguished by simplicity and solidity of construction, which is of great importance when this engine is used in agriculture.

The firm Climax exhibited five alcohol engines, of which four are vertical—of 6, 3, 3½, and 2 horsepower—and one horizontal of 13 horsepower. The engines are four-stroke and differ from other engines in the transmission of motion from the main shaft to the exhaust and inlet valves and in the arrangement of the flat regulator. The consumption of alcohol in these engines ranges from 0.3 to 0.5 liters per horsepower per hour, depending on the size of the engine.

Cross-section of the “Gnome” alcohol engine.

Fig. 10.

The Christoph factory (Niesky near Görlitz) exhibited two very good engines of the Altmann system—one of 20 horsepower and one of 30 horsepower. Both engines make 240 revolutions per minute. The consumption of alcohol is 346 grams per horsepower-hour at full engine load. The engines are horizontal, four-stroke. The ignition is magneto-electric. A special feature of these engines is the regulation and the method of cooling the cylinder with water. The regulation is carried out in such a way that, when the load is reduced, the quantity of both alcohol and air is reduced, i.e., the mixture always remains of one and the same composition and only the quantity of this mixture is regulated. This best regulation is achieved in the following manner. Alcohol-

the alcohol valve (a) (see Fig. 11) is set in motion by the lever (b) (see Fig. 12), which at the same time also sets in motion the intake valve shown in Fig. 12. Lever (b) presses with pad (c) on screw (d), which, through the rotating rod (e) (Fig. 12) and lever (f) (Fig. 11), opens the alcohol valve (a). Motion is transmitted to the throttle valve from the governor by means of levers i, h and rod e. Pad (c) can rotate about bolt (m), and it can be lowered or raised at will by screw n. When the governor sleeve is in its lower position, the throttle valve g is completely open and lever d is in the greatest—

Fig. 11.

Fig. 12.

The distances from the point of rotation of lever Ь change, and consequently the lift of the valve for the admission of alcohol will be greatest, i.e., the greatest quantity of admitted air will correspond to the greatest quantity of admitted alcohol, and vice versa. Thus the composition of the mixture always remains one and the same.

As a second feature of these engines, it is necessary to note the preliminary heating of the admitted air for the purpose of better and more reliable evaporation of the alcohol. The admitted air is heated by the heat of the exhaust gases, for which purpose the pipe carrying off the spent gases passes inside the pipe supplying the air. At full load of the engine, the air drawn into the cylinder may prove to be too hot, as a result of which premature explosions may occur; to avoid this latter circumstance, a rotating valve k is arranged in the air pipe (see Fig. 11), by opening which cold air can be admitted, thereby cooling the greatly heated intake air. The next feature of these engines, chiefly the locomobile ones, is the special cooling of the cylinder. The engine cylinder is placed in a special closed vessel (in the two-cylinder Daimler system the same principle of cooling), filled with water. During operation of the engine the water in the vessel boils, and the vapors are carried off through an existing pipe into the atmosphere. As the water boils away, fresh water is poured into the vessel. With such a method the consumption of cooling water is considerably reduced, namely to \(3/4\) liter per hour per horsepower, which, where water is in short supply, must be of enormous importance.

At the Berlin Institut für Gährungsgewerbe und Stärkefabrikation, engineer Fehrmann carried out a series of tests of a 15-horsepower alcohol locomobile of this factory *). The data from these tests are given in the following table.

*) Verein der Spiritus-Fabrikanten in Deutschland. Bericht über die Prüfung einer nominell 15-pferdigen Spiritus-Lokomobile der Maschinenfabrik Christoph.

In the experiments, the load was applied by a Brauer brake. To determine the consumption of alcohol, the vessel from which the alcohol was being consumed was carefully weighed before and after the experiment. The alcohol used consisted of 98% alcohol by weight (86% alcohol by weight) and 2% benzene. The calorific value of this alcohol was \(5581 \frac{\mathrm{WE}}{\mathrm{kg}}\). Taking into account the above data, the thermal efficiency was calculated; its value at different loads is shown in the following table:

For the sake of completeness, I think it not superfluous to mention the motors of the Dürr factory (Eilenberg bei Leipzig), which exhibited high-speed engines: one of 4 horsepower, with 800 revolutions, and one of six horsepower with 300–325 revolutions. The engines are vertical, four-stroke. The alcohol consumption is 0.5 liters per horsepower-hour. A distinctive feature is the evaporator.

An interesting engine was exhibited by the firm Deutz. The engine is 4 horsepower and makes 1000 revolutions per minute. In addition to this engine, the factory exhibited: one ten-horsepower stationary engine, with 200 revolutions, and one six-horsepower locomobile engine. Fuel consumption is 346 grams per horsepower-hour.

Daimler exhibited two 14-horsepower locomobile engines and seven stationary ones: two of 6 horsepower, one of 10 horsepower, two of 2 horsepower, one of 6 horsepower, and one of 4 horsepower on a single shaft with a dynamo machine. I have already spoken of these engines in describing the factory.

To finish with the exhibition, I shall also mention the firm Trauzl & Co., which exhibited a 10–12-horsepower locomobile engine working on alcohol or gasoline. Cylinder diameter 200 mm, piston stroke 320 mm; at 240 revolutions per minute the engine develops (maximum load) 16.5 horsepower. Consumption per horsepower-hour is 400 g of 90-percent alcohol or about 300 g of gasoline. Regulation of the engine is by the composition of the mixture.

In Vienna I inspected the Technological Museum, housed in two enormous, excellently arranged buildings. In addition to various kinds of machine tools, instruments, dynamo machines, and so forth, the museum contains a whole series of various explosion engines. This, in my opinion, is a remarkably useful institution. Anyone interested, say, in engines can see in this museum all the engines manufactured in Austria-Hungary in operation and compare them.

among themselves. This museum is of especially great importance for consumers and manufacturers.

Thanks to the courtesy of the museum inspector, engineer Jander, under whose direction tests are carried out on the engines delivered to the museum, I was able to acquaint myself with the test protocols of various engines. The test data for the engines most interesting to me have been grouped and placed in the following table.

Table *)

*) In the table, D and L are the diameter of the cylinder and the stroke of the piston—in millimeters. The magnitude of the load is shown in horsepower.

As can be seen from the table, the engine subjected to testing was the “Avans,” a type fairly widespread in Russia, which showed fairly good consumption, namely: when operating on petroleum, 0.504 kg per hour per effective horsepower, and when operating on petroleum residues—0.536 kg per hour per effective horsepower. I shall not describe this engine here, only because it has more than once appeared in our technical journals*), and I shall turn to a description of the “Alpha” engine, which I saw while passing through Moscow and which interested me by its complete similarity to the “Avans” engine. This similarity is so great that I refuse to find any difference whatever between these engines. For persuasiveness I present a drawing of the 2-horsepower “Alpha” engine at \(1/2\) natural size. The “Avans” engine differs, as we know, in the arrangement of the governor. The “Alpha” engine also has exactly the same governor, shown in Fig. 13. I shall take this opportunity to describe the action of this governor. By means of the eccentric A (see Fig. 13), the lever B is set into rocking motion; at the upper end of this lever is placed the balance weight C, sliding along the inclined plane D. When moving along the inclined plane backward and forward, the balance weight C strikes each time against the tooth E, connected directly with the rod of the pump piston that feeds kerosene or petroleum into the engine nozzle.

Fig. 13.

In the initial position (it is pushed back), the piston is driven by the spring F. When the number of revolutions of the engine increases, the balance weight C, owing to inertia, is thrown by the inclined plane D so high that it does not strike the tooth E, as a result of which the pump at this time does not feed kerosene or petroleum into the working cylinder, i.e., the so-called miss occurs. To stop the engine, one need only open the tooth E, setting it in the position shown in the drawing by the dotted line. Fig. 14 shows the details of this governor.

) See Bulletins of the Polytechnic Society*, 1903.

Regulator of the “Alfa” engine.
Throttle part and slide valve.

Fig. 14.

The nozzle of the “Alfa” engine likewise differs in no way from the nozzle of the “Avans” engine and is also provided with a copper cylinder A (see Fig. 15), having three screw cuts, for the purpose of better atomization of petroleum or kerosene. The vaporizer is likewise an exact copy of the vaporizer of the “Avans” engine. Moreover, “Avans” borrowed all its parts from the American “Mietz & Weiss” engine.

In the present year there appeared, attracting general attention, the Güldner motor, by the author of the well-known book on gas engines. Last month, in the Zeitschrift des Vereines deutscher Ingenieure (1904, issue 26, p. 979), the first published data appeared; making use of them, I should also like to say a few words about this new motor. This engine is vertical and operates in four strokes. The intake and exhaust valves are placed in the cylinder head. Between the valves is placed an electric ignition. The degree of filling of the cylinder is regulated, and at the same time, together with the quantity, the composition of the mixture is also changed.

In September of last year, Prof. Schröter carried out a series of tests with the Güldner engine, the results of which are placed in the following table:

Fig. 15.

Test data when operating on illuminating gas.

For the experiments, a 20-horsepower motor was taken; the diameter of its cylinder was 200.6 mm, the piston stroke 400.3 mm. When operating on illuminating gas the preliminary compression was brought up to 8 atm.; when operating on Dowson gas, to 11 atm. During the experiments, indicator diagrams were taken every 2–3 min. The exhaust gases were colorless and odorless, which indicates complete combustion of the mixture in the working cylinder of the engine.

Prof. Schröter gives, for the last row of this table, the following heat balance. When operating on illuminating gas, 42.7% of the heat is converted into indicated work, 33.2% is carried away by the cooling water, and the remaining 24.1% is lost in the form of heat radiation and is also carried away by the exhaust gases. As can be seen, in terms of heat utilization the Goldner motor truly deserves exceptional attention.

Prof. Schröter also carried out tests of this engine when operating on Dowson gas. These tests likewise gave very good results, since the indicated efficiency of the entire installation (including losses in the generator, scrubber, etc.) was 29%, while the motor expended 1700–1800 WE per 1 indicated horsepower. The detailed data are in the following table.

In this table, in the columns “brutto” the amount of anthracite is shown together with the consumption of combustible material used for kindling; in the “netto” columns this consumption is excluded. Used in

in these experiments anthracite (Marke Kohlscheid III) had the following composition:

The calorific value of this anthracite, determined by the calorimetric method, was taken as the average of two tests (7784 and 7775), namely 7780 WE/kg. The gently sloping form of the curve of fuel consumption per one effective horsepower per hour (see Fig. 16) indicates an insignificant increase in this consumption as the engine load is reduced. This latter circumstance must be counted among the most important positive qualities of the engine. The engine, as I have already said, is four-stroke, although the first engine (model of 1894) was two-stroke and horizontal. Güldner engines are built from 10 to 100 horsepower as single-cylinder engines, and from 75 to 200 horsepower as two-cylinder engines. The number of revolutions of the engines ranges from 240 (for 10 hp) to 160 (for 100–200 hp), depending on the size of the engine.

1 mm. = 20 gr.

Fig. 16.

In Dresden I inspected the Dresden Machine Factory and the works of Moritz Hille. “Dresdner Maschinenfabrik und Schiffswerft” (Leipzigerstr. 27, 29) manufactures steam engines of up to 1300 horsepower, of triple expansion with Kohlmann valve gear. High-speed steamship engines are also manufactured for vessels being built at the shipyard of this same factory. The distinctive form of the steam boilers built at the factory attracts attention. The flame tube in the front part of the boiler is made, as in the boilers of the Schulz-Knauht system, of corrugated iron; further on, the tube has a stepped form, increasing the heating surface and giving the tube elasticity. These boilers are built from 12

up to 150 sq. meters of heating surface, at a pressure of from 4 to 15 atm. Steam formation is about 30 kg per hour per square meter of heating surface. At the factory there is electric transmission. The current is obtained from the main factory station, where two steam engines are installed: one of 120 horsepower, two-cylinder, with Collmann valve gear, 200 revolutions; and a 300-horsepower engine, tandem, 120 revolutions, likewise with Collmann valve gear. On one shaft with this engine is a dynamo rated at 1500 amperes at 120 volts.

The Moritz Hille factory in Dresden formerly manufactured acetylene engines, but experiments showed that, at present carbide prices, the consumption of acetylene per horsepower-hour would amount to approximately 28–30 pfennigs. Of course, these engines cannot compete with alcohol or gasoline engines, the price of power per hour in which, as we have seen, has been brought down to 6.75 pfennigs (see p. 11). At the present time the factory manufactures engines operating on alcohol, or on gasoline, kerosene, and Dowson gas. The engines are horizontal, four-stroke, with electric ignition. In the seventeenth issue, which I received only today, of Mitteilungen über Forschungsarbeiten, Prof. Meyer published a series of tests on engines: Moritz Hille, Deutz, Dürr, Körting, A. G. Marienfelde, Oberursel, and others. All these engines have already been noted in my report, and therefore I consider it very appropriate to include here the data of Prof. Meyer’s tests relating to these engines, by means of which a comparative evaluation of the latter can be made.

The engines of interest to us, taken for experiments by Prof. Meyer, had the following dimensions:

All the motors in Prof. Meyer’s experiments ran on alcohol. Further, Prof. Meyer determined the time from the beginning of starting the motor until the first flash, until operation on the governor (to the governor play), until the admission of alcohol, and until the full load was applied. All the numerical data are placed in the following table:

Of course, one cannot give preference to one motor over another merely because it can be started a few seconds sooner than another motor; nevertheless, such a table is of great significance. Thus, for example, from this table it can be seen that engines not equipped with an alcohol preheater took alcohol sooner than engines with a preheater, and that they require the least time (Deutz) from starting until the application of full load.

The tests were carried out at maximum, normal, half loads and with the engines running idle; moreover, in each separate case the number of revolutions, brake load, number of misfires per minute, consumption of alcohol per effective horsepower per hour, oil consumption, consumption of cooling water per hour and per one effective horsepower per hour were determined. During the experiments the temperature of the incoming and outgoing cooling water, the temperature of the combustible mixture, and the temperature of the exhaust gases were measured. The load was produced by a Degn brake, a description of which I have already given (see p. 8). All these interesting data from Prof. Meyer’s experiments are given in the tables placed overleaf. From this table we see that all the motors operate with a fairly high preliminary compression, namely on average from 11 to 12 atmospheres (16–7), which also explains the high efficiency of alcohol motors. To bring the preliminary compression to such high limits—

*) All engines were started on gasoline.

*) The method of cooling by evaporation is described by me (see p. 23).

allows one, without fear of premature explosions, to admit water boiling in alcohol; this water has the same significance as in the Banki engine, i.e., it absorbs part of the heat for its own evaporation, thanks to which it becomes possible to obtain greater compression without fear of premature explosion. From the same table we see that the consumption of oil and cooling water per one horsepower (effective) partly increases as the load decreases, although the total consumption of water and oil (hourly consumption) decreases as the load is reduced.

For the summer semester I moved to Dresden, for I found it more useful first to attend the purely theoretical course on gas engines given by Prof. Mollier, and then, the following summer, to attend the course of Prof. Riedler, who devotes his chief attention to the constructive side of engines. The summer semester in Dresden began on April 18. While attending Prof. Mollier’s lectures on gas engines and refrigerating machines, I at the same time worked together with the students in the mechanical laboratory of the Polytechnic. The mechanical (new) laboratory of the Dresden Polytechnic, in respect of its equipment with gas engines and its method of instruction, is rightly placed among the foremost laboratories of Western Europe. This laboratory—a large building with a semi-basement, a 7-minute walk from the old Polytechnic—was built in 1901–1902 according to the plan of Prof. Mollier. The area occupied by the laboratory is about 1,500 sq. meters, of which 1,000 sq. m. are occupied by machines, while 500 sq. meters are allotted to the physics room, the professor’s office, the technical bureau, and the lecture hall. In the laboratory there are: 1) a whole series of internal-combustion engines, 2) a generating installation, 3) a refrigerating machine, 4) a compressor, and 5) a single-cylinder Corliss steam engine with boiler and superheater. One of the principal places in the laboratory is occupied by the internal-combustion engines. The hall of the upper floor of the laboratory is intended for small motors. Here there are: 1) an 8-horsepower Deutz gas motor, of old design, with a crosshead and ignition tube. The load of this motor is measured by a band brake fitted to the flywheel of the engine. 2) An 8-horsepower Körting engine; this is an engine of the latest design, and can operate, at will, on illuminating gas, Dowson gas, “air” gas, “water” gas, as well as on alcohol, benzine, or kerosene. The ignition is magneto-electric, and an arrangement has been made for counting the number of flashes in such a way that at each flash a stroke is made on a telegraph tape. The engine is equipped with a new elec...

Mollier electric brake, the schematic arrangement of which is as follows (see Fig. 17).

The brake frame (A) is placed on the shaft (a) of the flywheel (M). Electromagnets F₁ and F₂ are fastened to the frame on both sides of the flywheel. Thus the entire apparatus constitutes, as it were, a dynamo-machine, whose armature is the engine flywheel. The pressure of the brake is transmitted to decimal scales, where it is measured.

Fig. 17.

3) The Deutz kerosene two-cylinder motor completes the series of internal-combustion engines. In the basement story of the laboratory building there are: 1) a 70-horsepower motor, specially designed for laboratory purposes by the Deutz factory. This engine can operate either on generator gas, or Dowson gas, or “water” gas, or illuminating gas. The engine ignition is double, electric. The motor is started by compressed air. The air pump for pumping air is driven by an electric motor. The motor is also equipped with an electric brake, the system of Prof. Mollier. All the engines are furnished with revolution counters, indicators, thermometers, which make it possible to observe the temperature of the exhaust gases, the temperature of the incoming and outgoing cooling water, and the temperature of the air and gas being drawn in; there are devices for measuring the consumption of cooling water, and the quantity of water cooling the cylinder itself and its temperature are measured separately from the quantity of water cooling the cylinder head. For measuring the consumption of air and gas there are air and gas meters made by the Julius Pintsch factory in Berlin. 2) A generator apparatus, adapted for producing both air gas and Dowson gas and “water” gas; the gas obtained is collected in a gasometer with a capacity of 50 cubic meters. 3) A refrigerating machine, whose capacity is about 10,000 calories per hour. The compressor of the refrigerating machine is driven by a 15-horsepower electric motor. 4) A 3-cylinder air compressor, constructed so that it can operate

or with one, or with two, or else with three cylinders; when working with three cylinders the air can be compressed to 100 atm. The compressed air is collected in special (two) vessels, whose capacity, depending on the temperature, is determined by special formulas.
5) A single-cylinder steam engine with Corliss valve gear, with a locomotive-type steam boiler whose heating surface is 20 sq. meters, and a steam superheater. Work in the laboratory is conducted under the supervision of Prof. Mollier himself and his two assistants. All the students are divided into 4 groups; each group works in the laboratory for 4 hours a week. I attach the schedule of work in the laboratory for the summer semester of this year.

As already mentioned above, together with the students of the third group I carried out all the work in the laboratory, namely: the testing of the steam engine, the compressor, the 8-horsepower Koerting motor, the 70-horsepower Deutz motor, the generator, and the refrigerating machine. The data obtained, both by our group and by the other groups, are attached herewith (see pp. 37–43).

GENERATOR TEST DATA.

Heating value of the anthracite used . . . 7825 } cal./kg.
Heating value of the briquette used . . . 5475 } cal./kg.

*) During the first two days the experiments were carried out without preheating the air.

TEST DATA

Cylinder diameters: \(D_I = 260\) mm.
\(D_{II} = 220\) mm.

COMPRESSOR.

TEST DATA

Cylinder diameter 180 mm. Piston stroke 450 mm.

CORLISS STEAM ENGINES

\[ N_i = 0{,}04835\, p_i n. \]

Piston-rod diameter 40 mm. Clearance space 4.5%.

TEST DATA OF A 70-HORSEPOWER OTTO DEUTZ GAS ENGINE

Cylinder diameter of the engine \(d = 400\) mm.
Piston stroke 580 mm.

\[ N_e = 0{,}002653\,G.n. \]

Calorific value of the gas 4295 cal.

TEST OF AN 8-HORSEPOWER KERTING MOTOR OPERATED WITH DOWSON GAS

Cylinder diameter . . . 175,19 mm.  Length of brake lever 1219 mm.
Piston stroke . . . 341,7 mm.  Own weight of the brake . . 17,5 kg.

Magnitude of the clearance space:

a—during tests 1–4 = 1976,9 ccm.  b—during tests 5–8 = 1476,3 ccm.

DATA FROM TESTS OF THE REFRIGERATING MACHINE.

Investigation of the dependence of the coefficient of performance of the whole apparatus on the temperature of the brine solution.

Diameter of the compressor cylinder, 120 mm; diameter of the piston rod, 35.3 mm. Stroke of the piston—220 mm. Salt content in the solution—21%, freezing point of the brine solution—16° C., specific heat of the brine solution, 0.83.

All these data obtained from the tests will, in the winter semester, be worked out in detail by the students during practical exercises under the supervision of Prof. Mollier and his assistants, so that I hope to return to them again. In the summer semester, as I have already said, the tests were carried out by groups (about 20 persons in a group) and had the character, as it were, of preliminary

tests, having as their principal aim to train students in various individual methods of testing, such as: handling an indicator, a brake, a planimeter, air and gas meters, and so on. In the winter semester these tests will be repeated, with two or at most three persons in a group. Then I performed a gas analysis (once with the students and once independently) and several times determined the calorific value of gases.

Quantitative analysis of gases in the laboratory of the Dresden Polytechnic is done by Hempel’s method. The composition of the gas being tested is known—i.e., it is determined beforehand by carrying out a qualitative analysis. Thus illuminating gas, as we know, consists of the following constituents: $C_2H_4$ in vapor form, $CO_2$, $C_2H_4$ (gaseous form), $O$, $CO$, $H$, $CH_4$, and $N$. Taking 100 cubic centimeters of illuminating gas and passing this gas through absolute alcohol, we obtain a smaller quantity of gas, let us say 99.6; knowing, moreover, that alcohol absorbs the vapors of $C_2H_4$, we can say that in our illuminating gas there was $100-99.6=0.4\%$ $C_2H_4$ (vapor form). Further, by passing the gas successively through caustic potash, sulfuric acid, phosphorus, and $CuCl_2$, we determine the percentage content of $CO_2$, $C_2H_4$, $O$, and $CO$; for $KHO$ absorbs $CO_2$, $H_2SO_4$ absorbs $C_2H_4$ (gaseous); phosphorus absorbs oxygen, and $CuCl_2$—carbon monoxide. In the analysis we obtained the following numerical data.

\[ \begin{aligned} C_2H_4\ \text{(vapor)} &= 100-99.6 = 0.4\% \\ CO_2 \quad\quad\ \ & = 99.6-96.7 = 2.9\% \\ C_2H_4\ \text{(gas)} & = 96.7-95.2 = 1.5\% \\ O \quad\quad\quad\ \ & = 95.2-95.1 = 0.1\% \\ CO \quad\quad\quad & = 95.1-82.9 = 12.2\% \end{aligned} \]

Thus we still have 82.9 cubic centimeters, in which are contained marsh gas, hydrogen, and nitrogen; denote this quantity by $r$. To determine the quantities of $H$ and $CH_4$, we proceeded as follows. From the 82.9 ccm we took a sample $p=16.1$ cubic cm. This sample was mixed with a certain (arbitrary) quantity of air $L=$ (in our example) 90.7 ccm. Through this mixture of air and gas an electric spark was passed.

Thus the volume before combustion was $V_v = 16.1 + 90.7 = 106.8$. After the flash the volume obtained was $V_n = 81.3$ cubic cm. Consequently, $C_g = 106.8 - 81.3 = 25.5$ cubic cm was absorbed. The volume of gas obtained after the flash—81.3 cubic cm—was again passed through

caustic potash (KHO), in order to absorb the carbon dioxide formed during the combustion of methane
\((\mathrm{CH}_4 + 2\mathrm{O}_2 = \mathrm{CO}_2 + 2\mathrm{H}_2\mathrm{O})\); in this way the amount of \(\mathrm{CO}_2\) obtained was
\(a = 81.3 - 75.8 = 5.5\ \mathrm{ccm}\).

We can now determine the percentage content of \(\mathrm{CH}_4\) and \(\mathrm{H}\) according to the formulas*), namely:

\[ \%\,\mathrm{CH}_4 = \frac{r}{p}a = \frac{82.9}{16.1}\cdot 5.5 = 25.8\%; \]

\[ \%\,\mathrm{H} = \frac{r}{p}\frac{2}{3}\left(C_g - 2a\right) = 49.8\%. \]

Nitrogen is determined as the remainder:

\[ 100 - (0.4 + 2.9 + 1.5 + 0.1 + 12.2 + 25.8 + 49.8) = 8.3\%. \]

The calorific value of the gas was determined by means of the Junkers calorimeter, a description of which those interested may find in “Der praktische Maschinen Konstrukteur,” 17 Jan. 1901. The calorific value of Dawson gas determined by us by means of this calorimeter proved to be equal to 1165 calories. With this I permit myself to conclude the present report.

M. Yuzhanov.

Dresden, \(\dfrac{12\ \text{Aug.}}{30\ \text{July}}\) 1904.

) Gasanalytische Methoden* von Dr. Walther Hempel.

[[unclear: handwritten note]]

1/2 nat. size.

Alfa-Motor.

A. B. Motorfabriken, Göteborg

Visible labels in the drawing:

• Water
• Air
• Exhaust
• Oil / fuel
• Exhaust gases