Proceedings

of the Tomsk Technological Institute

of Emperor Nicholas II

Vol. 13. 1909. No. 1.

IV.

D. V. Frost.

Report on a Trip to the Urals in the Summer of 1907.

With an attached plan.

1–13.

REPORT

ON A TRIP TO THE URALS

in the summer of 1907.

Recognizing the importance of properly organizing in Russia the prospecting of magnetic iron ores, which has already been carried out for several decades in Sweden and America, I began, as early as 1904, to take an interest in this question. On becoming acquainted with the literature relating to it, I found nothing about the conduct of such investigations among us in Russia, although I had heard that magnetometric surveys existed in the Urals, chiefly at Mount Blagodat. In 1905 I intended first to acquaint myself theoretically with the organization of magnetometric surveys, with which aim, having obtained a foreign assignment for five months of free vacation time, I went to Freiberg, where at the local Mining Academy a course on the prospecting of magnetic ores was being given and practical summer exercises in this subject were being conducted by the specialist in this question, the now deceased Professor Ullrich. Having worked first in Freiberg and, toward the end, in Aachen, I intended in the autumn to visit the Urals and see how magnetometric surveys were conducted there, but unfortunately neither in that year nor in the following one was I able to carry out my intention, owing to the extremely unsettled times that prevailed in Russia and to the strikes then taking place. In 1906 I took foreign leave with the special aim of acquainting myself with the organization of the course and practical exercises in the prospecting of magnetic ores at the Leoben Mining Academy, where at that time this matter was conducted by the well-known Professor Dolzhal.

Having received theoretical preparation and having thoroughly familiarized myself with the literature on the prospecting of magnetic ores, in the spring of 1907 I asked the Council of the Tomsk Technological Institute to assign me for the summer to the eastern slope of the Urals, in order to become acquainted with the magnetic investigations of iron ores that were being carried out there.

I consider it not superfluous here to express my sincere gratitude to the Council of the Institute, which met my request and granted me an allowance for the proposed journey. I have already mentioned that I had found nothing in the literature about the conduct in the Urals of the magnetic investigations that interested me; meanwhile I had heard that such investigations at Mount Blagodat ...

D. V. Frost.

have been carried out for a long time and have a fairly broad scope. Assuming that investigations there were being conducted continuously, and that at the present time I could personally take part in them, I wished to make use for this work of the Tiberg-Thalén magnetometer ordered by Professor L. L. Tove for the Mining Cabinet, which L. L. Tove kindly placed at my disposal. Unfortunately, the magnetometer ordered from Sweden was delayed, and therefore I had either to go without the instrument or to seek one elsewhere. Thanks to the assistance of mining engineer V. D. Ryazanov, I was able to obtain a magnetometer from the Irkutsk Mining Administration.

In the last days of June I finally received the magnetometer and set out for the Krivinsky Works, near which lies the famous deposit of magnetic iron ore, Mount Blagodat. Having arrived and presented myself to the local mining authorities, I received the most benevolent reception and a promise of full assistance toward the aim I had set myself. To my disappointment it turned out that the surveys that interested me had not been conducted for 3–4 years, and that at the time there were not even any engineers familiar with this matter.

The only person more or less acquainted with these investigations proved to be a steiger, to whom I was directed in order to obtain the necessary information. First of all, I was shown the magnetometers used in the Administration’s mining work. The latter, five in number, of the Tiberg-Thalén system, but already of an obsolete design, bore the traces of long disuse. At the same time I was shown plans of the magnetometric investigations. In addition to all this, all the data kept in the archives concerning the conduct of magnetic observations were placed at my disposal.

The belt of magnetic iron ores stretches along the eastern slope of the Urals, at a distance of about 20 versts from the latter, and crosses the entire Goroblagodatsky District.

The first magnetic investigations of the iron ores date to 1898. In that year, as far as can be judged from the information available in the files of the Mount Blagodat Administration, a magnetometer was first used for the search for magnetic ores. These investigations were carried out along the slopes of Mount Blagodat. In the locality, preliminarily divided into a series of quadrilaterals, one side of which was parallel to the astronomical meridian, only the angles of inclination of the magnetic needle were measured. Although later the results of the measurements were plotted on plans, and points with identical readings were connected by curved lines, no conclusions were drawn from the resulting maps. Measurements of the angles of deflection of the magnetic needle by the method of sines or tangents were not made at all. Thus, although in one case there was

a magnetometer was used, but such observations could have been carried out with greater success with a simple Swedish compass. The latter was indeed used for this purpose simultaneously with the magnetometer. Thus, on November 10, 1898, the Administration of Mount Blagodat instructed the superintendent of the Nizhne-Turinsk plant to obtain from the Administration a Swedish compass in order to carry out a magnetic survey near the village of Elkina, on the eastern slope of the Urals, in a locality called “Rudyanaya Yama,” where, according to the plan of exploratory work, prospecting was to be carried out.

More detailed magnetic investigations of iron ores on Mount Blagodat date only to 1899. Thus, in that year exploration was carried out on the area of allotment II of the Goroblagodatsky mine, on the northern slope of Mount Blagodat, between workings No. 11 and No. 9 and the Knyaze-Mikhailovsky mine. The instrument used for the prospecting was a Tiberg-Thalen magnetometer.

With the aid of these investigations, two trends of deposits of magnetic iron ore were found; one of them extended from the Knyaze-Mikhailovsky mine to working No. 11, and the other from the same mine to working No. 9.

In the same year, magnetic explorations of the Anferovsky deposit of magnetic iron ore were undertaken and completed in the autumn. The latter occupies the southern part of the second allotment of the Nadezhdo-Kommerceky mine. This deposit received its name in honor of the person who discovered it, a resident of the Kutvinsky volost, Dmitry Anferov, who while mowing his hayfield found excellent pieces of magnetic iron ore, which he brought to the Administration of Mount Blagodat.

It should be noted that the discovery of this deposit, as of many others, was not due to magnetic investigations, which is of course explained by the limited spread of the latter.

In 1900, with the opening of credit for exploration, the prospecting of the supposed ores was begun by means of pits and hand diamond drilling. It turned out that the deposit is a bed-like body of magnetic iron ore, having a strike of NO—SW and a dip in the SO direction. By prospecting, the deposit was traced along its length for 33 sazhen and down dip for 8 sazhen. The average thickness of the deposit reached 2 sazhen. If the volume of the explored part of the deposit is taken as 528 cubic sazhen, and the weight of one cubic sazhen of magnetic iron ore as 2000 poods, then the total reserve of ore is expressed as 1,056,000 poods. In the same year, 1899, the so-called Nazarovsky deposit was discovered by magnetic investigations. The latter is located 6 versts south of the Kushvinsky plant and 1 verst from the Ivanovsky deposit. Exploration by pits and boreholes was begun in the summer of 1900 and continued during the summer months of the following years. Explor—

D. V. Frost.

... by whom the presence of a bed-like deposit of magnetic iron ore of excellent quality was discovered. This deposit has an average strike of NO—SW and has been traced for 105 sazhens along the strike.

Where it comes to the surface it is covered by a layer of peat ½–2 arshins thick. Over the indicated extent the deposit was explored to a depth of 10 sazhens. The thickness of the explored part of the deposit is determined on average at 2 sazhens, while its dip ranges from 45° to 65° over 50. On the basis of the data cited, the volume of ore in the explored part of the deposit may be taken as 3300 cubic sazhens, or, reckoning 1 cubic sazhen of iron ore at 2000 poods, the total reserve of ore at 6½ million poods.

Apart from the aforementioned deposit of magnetic iron ore, the surrounding locality is rich in separate boulders of the latter, sometimes reaching a weight of 60 poods and more. These boulders lie no deeper than 1–2 arshins from the surface, and many of them are excellent natural magnets.

Magnetic surveys in the Goroblagodatsky District reached their greatest development in 1900. On January 20 of that year, at the local Mining Council, under the chairmanship of the Mining Chief, it was resolved, in view of the forthcoming land settlement of the inhabitants, to carry out magnetometric investigations along the belt of occurrence of magnetic iron ore in those localities which were to pass under allotments, so as not to allot to the inhabitants land containing ore. For this purpose it was decided, for the conduct of magnetic surveys, to invite students of the Mining Institute, according to the number of instruments available. By that time the Administration of Mount Blagodat had one magnetometer, and in addition the District Administration ordered three more such instruments. Thus it was planned to organize 4 parties and at first to entrust the local draftsmen with conducting the surveys, and upon the arrival of the students to hand over to them the work begun with the magnetometer, while the draftsmen were to be entrusted with plotting the surveys on the plan and with calculations. It was proposed to begin the magnetic observations in the month of May and to finish them in September, i.e. to complete the whole work within 5 months, reckoning 25 working days per month. The cost of the work of one party was determined as follows:

and consequently for 4 parties, 4000 r.

In 1900 magnetometric observations were carried out to the north of the sixth and fourth allotments of the Blagodat iron mine, to the south of the first one near the Korablevka River, to the south of the Laya road, and along the Salda road.

One of the largest surveys made with a magnetometer in that year was the survey of the Ivanovskoe deposit of magnetic iron ore. In the summer of the above-mentioned year, magnetometric prospecting was carried out by a student of the Mining Institute in the area of the Kushva dacha, on the left side of the Korablevka River, between this latter and the Malaya Kushva River. Observations were made from the initial point southward every ten sazhen. At each point both the angles of declination and inclination and the angles of deviation were determined by the method of sines and tangents. In view of the intensity of the change in the above-mentioned angles during observations in this locality, it was decided to proceed here with a geological survey. The latter was carried out in 1901 by mining engineer Ivanov, as a result of which the deposit discovered by the survey received the name of the Ivanovskoe deposit. It is located near the Malaya Kushva River, at a distance of not more than 5 versts south of the Kushva works. During the surveys here, four bed-like deposits of magnetic iron ore of very good quality, rich in iron content, were found, occurring among feldspathic rocks. The deposits of magnetic iron ore have a strike of NO—SW and a dip almost to the east or southeast at an angle of about 45°, i.e., in the nature of their occurrence, the deposits of magnetic iron ore are very close to the deposits on Mount Blagodat. Between deposits No. 3 and No. 4 there are also ores of magnetic iron ore, but poorer in iron content, since they contain inclusions of feldspathic rocks. Ores of the same quality were also found in the hanging wall of deposit No. 4. Between deposits No. 2 and No. 3 the feldspathic rocks contain an admixture of magnetic iron ore to a greater or lesser degree. All 4 deposits have been traced by shafts and boreholes sunk from some of the shafts. Deposit No. 1 has been determined over a length of 26 sazhen, its average thickness being 0.7 sazhen. Deposit No. 2 has been traced along the strike for 50 sazhen with an average thickness of about 2 sazhen. The strike of deposit No. 3 is 30 sazhen, and its thickness is 1 sazhen. Finally, deposit No. 4, with the same strike as the preceding one, has a thickness on average of about 2 sazhen. Taking into account also the ore occurring between deposits No. 3 and No. 4 of magnetic iron ore, their total thickness may be considered equal to 5 sazhen. The greatest depth reached by the survey is 8 sazhen. Accordingly, the volume of magnetic iron ore discovered by the survey,

will amount to 2,370 cubic sazhens, or the total reserve of the deposit will be equal to 4,740,000 poods.

The confirmation, by magnetometric investigations in the locality between the rivers Korableskaya and Malaya Kushva, of the occurrence, as found by detailed prospecting, of rich ores of magnetic ironstone lying no deeper than 1½–2 arshins from the surface, showed the undoubted usefulness of work with a magnetometer; and, as a consequence, the Manager of all mining operations at Mount Blagodat was petitioned for an appropriation of 2,000 rubles for the continuation of these investigations. The conduct of the work was entrusted to two mining engineers, superintendents of the Serebryansky and Baranchinsky plants. However, in view of the too-late appropriation of funds in 1901 for magnetometric investigations, the latter were carried out chiefly only between the river Kushva and the Alferovsky deposit of magnetic ironstone. The prospecting of the Ivanovsky deposit along strike and dip, as well as the search for new deposits of magnetic ironstone in this locality, was carried out in 1902. In that year, in accordance with the order of the Mining Chief, the magnetometric investigations were conducted almost exclusively on lands not yet leased to private persons, namely in the third, fourth, and sixth allotments of the Blagodat iron mine.

In these allotments the magnetometric observations were made in the vicinity of the Vysokogorsky mine, situated on the Second Vysokaya Mountain, 2½ versts from the Kushva plant along the Verkhne-Turinsky road, and also in the interval between the Vysokogorsky and Blagodatsky mines, with the aim of finding new occurrences of magnetic ironstone. In addition, in 1902 magnetometric observations were begun on the Second Ob"ezdnaya Mountain, 2 versts from the Verkhne-Turinsky plant, and on Vysokaya Mountain. Ob"ezdnaya Mountain is also located on the Verkhne-Turinsky road, between the Polovinka River and the Verkhne-Turinsky plant, 2 versts from the latter. Prospecting in 1896 here revealed a deposit of magnetic ironstone 0.33 sazhen thick. The deposit was traced along strike for 112 sazhens and along dip to a depth of 10 sazhens. The direction of strike of the deposit is NW and the dip is at an angle of 30–35°. The shafts showed that with depth the thickness of the sheet-like deposit increases and reaches up to 3 arshins. The ore reserve was determined at 746,000 poods.

Since in the Goroblagodatsky District sheet-like deposits usually occur in whole suites, it was decided, in order to find new occurrences parallel to the known one, to resort, for preliminary prospecting, to the magnetometer, as the cheapest method in comparison with shafts and cuts, which, in the hard plagioclase and feldspathic porphyries, required costly and slow blasting work.

In 1903 the magnetic surveys, as preliminary prospecting, were carried out: 1) on Vtoraya Ob”ezdnaya Mountain, 2) on the Safonovsky coal-burning site near the village of Plotinka, 3) between the old and new Baranchinsk roads at the so-called Krutoi Log, and 4) on Magnitnaya Mountain. On Vtoraya Ob”ezdnaya Mountain the intention was to continue the magnetometric observations begun in 1902, with the aim of finding the continuation of the deposits of magnetic iron ore discovered by exploratory shafts in 1896. On the Safonovsky coal-burning site, pieces of magnetic iron ore were encountered very often; in their properties they were very close to the magnetic iron ore of the Anferovsky deposit at the Nadezhdo-Kommerchesky mine. The presence of magnetic iron ore at the Safonovsky coal-burning site, and the location of the latter within the belt of distribution of magnetic iron ores, involuntarily suggested the idea of undertaking prospecting here with the aim of finding new deposits. The locality at Krutoi Log likewise lies within the belt of distribution of magnetic iron ores, and therefore it was decided to investigate this locality as well with the aid of a magnetometer; however, the work here was not completed, since, judging by the readings of the instrument, which gave angles close to neutral, no occurrence of magnetic iron ore was expected here.

In July 1903, pieces of magnetic iron ore were found by the manager of the Baranchinsk plant along the Starotagil road, scattered in great abundance along the road. In view of the excellent qualities of the ore found and the presumed proximity of the deposit, it was decided to carry out magnetometric observations here. Since the latter did not yield favorable results, on the basis of questioning local inhabitants it was assumed that the pieces of ore found had come here from old workings on Magnitnaya Mountain. The latter is located 12 versts from the Baranchinsk plant along the Laisk road. Investigations with a magnetometer were carried out here, but not complete ones—only the determination of the angles of inclination.

Despite the presence on this mountain of ancient workings, some of which had the appearance of open workings while others had the character of adits, and despite the characteristic readings of the instrument, with the value of the angle of inclination varying from 8° to 90°, and the attraction being sometimes northern and sometimes southern, more detailed investigations here apparently were not subsequently carried out.

The cost of the magnetometric surveys in 1903 was considerably less than in 1900. The expenses for work with the magnetometer amounted to the following sum: on Vtoraya Ob”ezdnaya Mountain and on the Safonovsky coal-burning site, 250 rubles each, and around Krutoi Log, 300 rubles.

All these surveys were carried out by students of the Mining Institute under the direction of engineers.

In other places in that year magnetometric surveys were not carried out, as is said, owing to the lack of personnel for conducting these works, but more probably owing to a loss of interest in these prospecting operations, confirmation of which may be seen in the fact that in the following years there were no longer any such observations either.

Of all the magnetometric investigations described in the period between 1899 and 1903, the best results were yielded by the investigations in the tract near the Korablevka River, where the Ivanovskoye deposit was subsequently discovered, at the Anferovskoye deposit, and in the interval between the latter and the Korablevka tract—precisely in those places which became part of the allotments of the Nadezhdo-Kommerchesky mine. In other places where magnetic prospecting was undertaken, the results were less favorable.

Summarizing all that has been set forth above, we see that the magnetometric observations in the Goroblagodatsky district had the character merely of preliminary magnetic prospecting—that is, of such investigations as could be carried out quite successfully and without such an expenditure of time and labor with the aid of an ordinary Swedish mining compass. Usually, in these observations, they merely watched the degree to which the readings of the instrument changed and, judging by their magnitude, drew conclusions as to the possibility of finding magnetic iron ore in one locality or another. Further exploration was always reduced to the driving of a number of shafts and boreholes. Not to mention the fact that no conclusions were drawn from the results of the magnetometric investigations regarding the number, position, and form of the magnetic deposits, often even the curves of the lines of force were not plotted on the observation plans. This circumstance becomes quite understandable if we take into account that, in general, in the Goroblagodatsky Mining District there were no persons more closely acquainted with the organization of magnetic prospecting. Apparently the only individual who understood the full importance of magnetometric observations was the former manager of mining works, mining engineer Nik. Nik. Anikhtin. Being a supporter of the use of the magnetometer for prospecting for magnetic ores, N. N. Anikhtin unfortunately had no opportunity himself to study this method more closely and had no persons under his supervision who were acquainted with, or wished to become more closely acquainted with, these investigations. The observations themselves were carried out, as we have seen, chiefly by students of the Mining Institute, predominantly from the lower courses. If we add to this that at that time, as almost even now, there was nothing in Russian literature on the prospecting of magnetic ores, apart from two or three translated articles, the inadequacy of the organization of work with the magnetometer becomes understandable, all the more so in the absence of experienced supervisors.

The students who carried out the work, being unable to draw any conclusions from the results obtained during the survey, and regarding their studies as almost useless, naturally could not treat this work with particular attention.

The work was conducted unwillingly and therefore extremely slowly. What could have been completed in the course of a month was stretched out over several months. As a result, the cost of the work increased considerably. With the funds allocated for magnetic prospecting in 1900 and 1903, it would have been possible to carry out far more substantial explorations. Having familiarized ourselves with the arrangement of the magnetic observations on Mount Blagodat, we first of all do not see in these works the proper systematic character. All the prospecting had a somewhat accidental character: in one place it was carried out, in another it was not. In general, no special importance was attached to these investigations, and they were resorted to as an auxiliary method of prospecting, being called forth by necessity, as was the case with prospecting on those lands which were later to pass under workers’ allotments. But even here one notices a stereotyped approach. Since no preliminary observations with a Swedish mining compass were made, and since, immediately after a given locality had been divided into a series of squares, direct measurements with a magnetometer were carried out, it often turned out, after a great deal of work had already been completed, that no ores whatever could be expected in that locality. In other cases, magnetic observations were made near already known, rich deposits of magnetic iron ore in order to find new ores, and the influence of the known deposits was in no way taken into account, as, for example, in the measurements along the slopes of Mount Blagodat. Obviously, under the action on the instrument of such a large deposit as Blagodat itself, the discovery of new deposits is a very difficult task, requiring an especially attentive attitude. Taking into account such conditions in the organization of prospecting, we should not be surprised that very often, if not more than often, these prospecting efforts proved completely fruitless and were not even brought to completion. The results obtained were sometimes so complex and so irregular that it was impossible to judge from them the distribution of the dynamical curves. In such cases the said curves were drawn either without any definite rule, or else they were not drawn at all; and, as has already been said, the presence or absence of ore deposits was judged solely from the intensity of the change in the instrument readings. Needless to say, the magnetic maps were not compared with the geological maps for the same localities, as is always done in Sweden. It was not difficult to confirm all that has been said by facts. Thanks to the particular courtesy of the Administration

…with Mount Blagodat, all the maps of the magnetic surveys that had been carried out were collected by me. I consider it necessary to note here as well that many magnetic maps of Mount Blagodat have already disappeared, which in any case represents a great loss.

Even with such an abnormal manner of conducting magnetometric surveys, thanks to them indications were obtained of the existence of such rich deposits of magnetic iron ore as, for example, at the Anferovskoye, Nazarovskoye, and Ivanovskoye deposits. The failures of magnetic prospecting in other places are explained either by an incorrect choice of the area of observation, which was often located either in a region where the deviation of the compass needle from its normal position was barely noticeable, or near already known deposits, in which case the strong influence of the latter made the presence of new ores imperceptible. In general, all failures may be attributed to an insufficient ability to interpret magnetic maps correctly.

The inexpediency of conducting magnetic observations becomes especially clear if one becomes acquainted with these methods of prospecting in places where they have long acquired broad citizenship rights, as, for example, in Sweden. Not considering it convenient here to touch in detail upon the organization of work with the magnetometer in the country mentioned, and intending to make this the subject of a subsequent article, I nevertheless find it not superfluous below to touch upon this question at least to the extent necessary to see what could have been expected from the organization of work with the magnetometer.

So far as I was able during this summer’s trip, together with Professor of the Mining Institute V. I. Bauman, to become acquainted in Sweden with the organization there of magnetic prospecting, these observations are regarded as necessary in every exploration for magnetic ores.

Having received, with the aid of the Swedish mining compass, indications concerning the presence of magnetic ores, more detailed investigations are carried out with the magnetometer. After making a survey and obtaining on the map a system of curves of horizontal and vertical intensity of the given magnetic field, they at once try to draw the necessary conclusions concerning the number of deposits, their strike, dip, and depth of occurrence. Of course such conclusions are made in connection with the available geological data. Only after such preliminary considerations do they proceed to detailed exploration by means of boreholes and shafts. Subsequently the magnetic maps are compared with the geological ones, as a result of which it becomes possible to verify the degree of reliability of the conclusions drawn on the basis of the first maps. As the deposits are worked out…

deposit, the magnetic survey is repeated and continued further. Repetition of the survey is of great importance, since it makes it possible to take into account the influence of the mined-out ore mass and consequently to prepare valuable material for future prospecting.

In investigations during the course of the mining itself, both for the purpose of finding new nests and also richer parts of the deposit, very great benefit is rendered by the so-called measurements of lines of force (kraftpilmätning). Thanks to the latter it has been possible to follow unerringly along the path of the ore nests, avoiding at the same time the vain and fruitless driving of crosscuts.

In general, in Sweden enormous importance is attached to magnetic investigations. In addition to the fact that magnetic observations are carried out at every mine, as has already been mentioned, in recent times such investigations have been undertaken on a more extensive scale with a purely scientific formulation, for which local mine owners spare no funds. I was able to become acquainted with the production of such prospecting from the words and from an article by the professor of the Mining Academy in Stockholm, W. Petersson, who personally carried out such prospecting in the northern part of Sweden. The aforementioned article by Prof. W. Petersson was published in the journal “Jern Kontorets Annaler” for 1900 and contains a description of the formerly little-known ore-bearing parts of the Iukkasjärvi region and adjacent areas.

An even newer example of extensive scientific magnetic investigations is provided by the studies of the scholar V. Carlheim-Gyllensköld, briefly described in his recently published article (Sammanfattning af hufvudresultaten af magnetiska undersökningar vid Kiirunavara malmfält i Norrbottens län utförda under åren 1900—1905). The article cited, an offprint of which I received from the author, contains, as the title itself indicates, a survey of the principal results of the investigations in the ore region of Kiirunavara in Norrbotten, carried out in 1900–1905.

The magnetic intensities obtained in this region are reduced to absolute terrestrial magnetism and expressed in the C G S system. In his investigations V. Carlheim-Gyllensköld proceeds from the interesting representation of the deposit in the form of a compressed ellipsoid or an elliptical cylinder.

Without entering here into the details of the content of both extremely interesting articles, I wish only to point out how seriously magnetic investigations of iron ores are treated in Sweden. Independently of the broad practical formulation of this question, in Sweden great importance is also attached to the theoretical development of methods of investigation. At the Stockholm Mining Academy practical exercises are conducted in the course on prospecting for magnetic ores, with surveys being made in a magnetic field created artificia—

by magnets of various forms and positions. In the summer, students carry out magnetic surveys in places where magnetic ores occur. Thus, in the summer of this year similar surveys were carried out, under the direction of Professor W. Petersson, in central Sweden at the Clacka-Lerberg mine. In the planned new building of the Mining Academy in Stockholm, for which considerable funds have already been allocated, it is proposed, according to Professor Petersson, to establish a special magnetometric laboratory.

In view of the fact that in the Urals our deposits of magnetic iron ore have much in common with the Swedish magnetic ores, a proper organization of magnetic prospecting is extremely timely. Even now, in the opinion of practical engineers, the need is felt for prospecting in the Urals for new iron ores.

Outcrops of magnetic iron ore are quite frequent, and yet considerable funds are needed for the ordinary exploration of these places. In this case, investigations with a magnetometer could bring great benefit and prevent large unnecessary expenditures on exploration by shafts and boreholes. With the proper organization of magnetometric prospecting, it is extremely inexpensive and could be successfully carried out by students under the direction of engineers familiar with these investigations.

One can only hope that the mining enterprises of the Urals which are in need of finding new iron ores will turn their attention to the indicated method of prospecting and will not begrudge the small expenditures required for it.

A particularly proper organization of magnetometric prospecting should be expected from state mining enterprises, such as, for example, the Goroblagodatsky Mining District. One cannot help regretting that in the latter the magnetometer was not properly used in former times. Otherwise we would possess rich material that would have great scientific and practical significance. Magnetic prospecting on Mount Blagodat is all the more necessary at the present time, when, owing to the working out of the main deposit or because of an increase in the admixture of cupriferous pyrite to the magnetic iron ore in the lower horizons, it is necessary to seek new deposits.

The application of the magnetometer in prospecting acquires still greater importance in countries that have been comparatively little investigated, where it is necessary, in a comparatively short time and without great expenditure of funds, to form an idea of the presence of magnetic ores.

Thanks to the more compact magnetometers that have appeared in recent times, such as the magnetometers of Delbloem, Thomson–Thalen, and

finally, of the American type, this instrument may serve as a companion to any geologist in his field investigations.

In concluding the present article, I shall be very pleased if it draws the attention of practicing engineers to the magnetometric method of prospecting for magnetic ores.

Dm. Frost.

Berlin, December 1, 1908.

Plan of part of the Kushva [[unclear: estate/dacha]]

from the survey by the [[unclear: forest/mining]] sub-detachment in 190[[unclear]]

Map labels visible on the plan

• Tura River
• Verkhne-Turinsky [[unclear: road/route]]
• Center; [[unclear: established by the detachment with a magnetometer]] in 1900.
• R. Bobrovka
• Verkhne-Turinskaya [[unclear]]
• Bolshoi-Blagodat iron-ore mine
• Kushva Works
• Kushva Pond
• Saldinskaya Road
• Novaya Road
• Kedrovsky Mine
• Malo-Blagodatsky Mine
• [[unclear: Sargovsky/Sarkovsky]] Mine
• Baranchinskaya [[unclear: road]]
• Scale

Numbered areas and grid markings visible

• 9
• 11
• 20
• 21
• 22
• 31
• 32
• 33
• 42
• 43
• I
• II
• III
• IV
• V
• VI
• VII
• VIII
• IX
• X
• XI

Scale

0–5 versts, with subdivisions marked in sazhen at the left end of the scale.

Plan

of part of the Kushva dacha, compiled from the survey by officials of the land-settlement detachment in 1901–1903.

Visible inscriptions on the plan

• Forest.
• Center of the deposit determined by magnetometer in 1900.
• R. Polovinka.
• Verkhne-Turinskaya dacha.
• M.-Blagodat magnetite mine.
• N.-Turinskaya dacha.
• Malo-Blagodat mine.
• Saldinsky.
• [[unclear: handwritten locality name]].
• [[unclear: handwritten mine/locality name]].
• 5 versts.

Visible numbered compartments / sections

IV, V, VI, VIII, IX, X, XI, 12, 13, 22, 23, 24, 33, 34, 35, 43, 44, 45.