Imágenes de páginas
PDF
EPUB

Rarely attempted. Answers with two exceptions very bad. In some cases a poor drawing of a copper furnace was given At this stage all students ought to be well acquainted with the form and construction of typical modern water-jacketed furnaces used in copper smelting and lead smelting respectively.

ores.

SECTION IV. Q. 49. State as fully as possible the conditions which are essential to success in the “

pyritic” or “raw sulphide” smelting of copper Somewhat less than half of the candidates attempted this question, and the answers, with a few exceptions, were extremely disappointing.

This important smelting process appears not to have been taught in many schools, or if taught, the teaching is far from efficient. As the process is now coming extensively into use wherever the ores are pyritic, and is rapidly replacing the old methods on account of its greater economy, all students at this stage ought to be well acquainted with it, and especially with the conditions under which it can be successfully employed. Q. 50. State fully how you would treat, on a large scale, “white metal”

containing 10 ozs. of gold per ton, in order to obtain the gold and the copper in marketable forms. If the white metal contained 100 ozs. of silver per ton, in addition to the gold, how would

you proceed? This question on practical work was attempted by rather less than onethird of the candidates and was fairly well answered. Q. 51. Describe the Mond (nickel carbonyl) process for the extraction of

nickel from a copper nickel matte. The chief errors in the answers were :-treating the matte with water gas without previous calcination, and changing the copper nickel oxide into the volatilizer without previous reduction,

HONOURS.
Results : 1st Class, 2; 2nd Class, 1 ; Failed, 7; Total, 10.

PAPER 1.
There were only 10 candidates, the number last year being 16. Eight
were examined in Section II. Iron and Steel, and two in Section III. : Gold,
Silver, Lead, &c.

Four only in Section II. obtained sufficient marks to qualify them for admission to the practical examination and the examination in Paper II.

The average standard of attainment of the whole of the candidates was practically the same as last year, but the average of the qualifying marks obtained by those who passed the examination in this paper was much lower, and closely approached the minimum required.

The greatest weakness was shown in the answers to the questions on working drawings and on the microstructure of steel.

None of the candidates had a clear understanding of what is meant by working drawings. They are the drawings which are required by the furnace builder to enable him to erect a furnace, and for a reverberatory furnace usually comprise the following :

1. Vertical section on the median line. 2. Horizontal section at the datum line and plan of the foundations. 3. Vertical transverse section at the widest part of the bed. 4. Vertical transverse section through the firebox. 5. Front elevation. 6. Side elevation. 7. Plan.

PRACTICAL.

STAGE 1.

Results: 1st Class, 36; 2nd Class, 41 ; Failed, 20; Total, 97. The number of papers sent in for this stage was practically the same as last year, there being 97 papers as compared with 99 in 1906. The standard attained by the majority of the candidates was good, while those who failed to pass showed a better knowledge of the subject than those who failed last year. Thirty-six qualified for the First, and forty-one for the Second Class.

In the preparation of the alloys, a number of the candidates were evidently unsuccessful owing to the furnaces at their disposal not giving a sufficiently high temperature for alloying the copper and iron in the copper-zinc-iron alloy, and the copper and nickel in the copper-nickel-zinc alloy, which they had to prepare.

It is possible that in some instances the low temperature may have been due to the furnaces not being prepared for the candidates before the hour of the examination. In all laboratories, especially those in which the draught of the chimneys is not particularly good, the fires should be lighted some time before the commencement of the examination.

In a number of instances in the preparation of the copper-zinc-iron and the copper-zinc-nickel alloys, the results were masses of metal with pieces of iron or nickel distributed through them. Some candidates did not cover their metal with carbon, during the fusion, while a few used coke as a covering, but this cannot be considered satisfactory.

As was also the case last year, many of the samples of metal were not properly cast, and in others the fractured surfaces indicated that the ingredients had not been weighed in the proper proportions before melting.

The preparation of coke from the samples of coal supplied was well done by most of the candidates, but in some cases the temperature at which the coking had been performed was too low. The results of the examination show, however, a general improvement on those of last year.

STAGE 2. Results : 1st Class, 30; 2nd Class, 48; Failed, 38; Total, 116. The number of papers sent in showed an increase of 27 on those of last year. The exercises given were as follows :

(C) Extract the silver, by a dry method, from the German silver supplied.

(D) Extract the lead from the ore-galena and zinc-blende supplied.

(CC) Extract the silver from the “hard” lead supplied.

(DD) Extract the lead from the "grey" slag supplied. Exercises C and CC were, as a rule, correctly carried out, although, in the case of the latter, the impurities were not always removed by scorification. Some candidates did not give sufficient attention to the temperature necessary for the cupellation of the lead for silver, and many did not properly clean the beads obtained, thus getting inaccurate results.

Exercises D and DD were performed in a satisfactory manner by about 50 per cent. of the candidates. In some cases insufficient reducing agent was added, resulting in a very low extraction.

Little attention seems to have been paid to the remarks made in the report of last year regarding the necessity for removing all adherent slag or other material from the buttons of lead and silver before weighing. The weight of a button coated with slag cannot possibly give the correct weight of the metal. In future, the marks awarded to candidates who do not return properly cleaned buttons will be few or none.

STAGE 3.

Results: 1st Class, 19; 2nd Class, 36; Failed, 26; Total, 81. The number of candidates last year was 77 ; on that there is an increase of four in the present.

The work compares most favourably with that of previous years except in the determination of phosphorus in pig-iron. This exercise was attempted by 47 candidates, of whom 22 failed to obtain a single mark. In most of the latter cases the failures would seem to have been chiefly due to defective manipulation. The results ranged from 0-56 to 4:40 per cent.

The determination of lime in dolomite was, as a rule, fairly well done, but several candidates omitted to separate the silica or the iron and alumina, before precipitating the lime, and others had imperfectly ignited the calcium oxalate precipitate.

The determination of gold and silver in copper was also fairly satisfactory, but the best method was not generally selected. The ordinary mixed ** wet and dry" method (with the addition of lead acetate to the original solution) should have been used. Scorification could only be successful in experienced hands.

HONOURS. Results : 1st Class, 2; 2nd Class, 1 ; Failed, - ; Total, 3. The three candidates who were finally qualified for admission to the practical examination in the Metallurgical Laboratory at South Kensington and the examination in Paper II., presented themselves, and ali passed.

The practical work in the laboratory was well done and the questions in Paper II. were generally well answered.

Report on the Examinations in Elementary Science of

Common Life (Chemistry).

EVENING EXAMINATION. Results : 1st Class, 151 ; 2nd Class, 130; Failed, 81 ; Total, 362. The students of this subject have acquired a knowledge of a great many facts, but whether from youth and inexperience, or defective teaching, they have not learnt to use these facts intelligently. Hence, many of the statements in their papers are not answers to the questions given, but apparently represent all they know about the subject. Several misconceptions are also very prevalent, e.g., that air from the lungs is carbon dioxide and nothing else, that coal contains coal gas, etc. Another point which requires attention is the unusual amount of irrelevant matter, quite unconnected with the subjects of the several questions, contained in many of the papers.

These are defects which can be eliminated by the use of a little care on the part of the teachers, and some practice in writing answers to questions.

DAY EXAMINATION. Results : 1st Class, 187; 2nd Class, 131 ; Failed, 38; Total, 356. The papers were, on the whole, good, but the chief defect generally noticeable seems to arise from the tendency to keep the facts acquired in compartments, and the inability to apply them in new and unfamiliar cases.

Questions in Section IX. of the Syllabus were answered less frequently than those in the other Sections.

GROUP V.-GEOLOGY, MINING, AND PHYSIO

GRAPHY

BOARD OF EXAMINERS. XII. Geology

J. W. Judd, C.B., LL.D., F.R.S.,

Chairman. XIII. Mineralogy

Sir J. N. Lockyer, K.C.B., LL.D., F.R.S. XVIII. Principles of Mining B. H. Brough, A.R.S.M., F.G.S. XXIII. Physiography

Report on the Examination in Geology. The very marked increase in the number of papers in this subject which was noticed last year has been more than maintained in the present year; and, what is of still greater importance, the striking improvement in the answers is as conspicuous as it was in 1905. There is clear evidence from a perusal of the papers sent in that both teachers and students are keenly alive to the interest of the subject, and to the value of Geology as a means of education, both in encouraging out-of-door studies and in inculcating habits of observation.

STAGE 1. Results : 1st Class, 64; 2nd Class, 87 ; Failed, 62 ; Total, 213. It is in this part of the examination that the results are least satisfactory. There is a slight falling off in numbers, and the answers are not quite so good as last year. But the answers are evidently written by pupils with very little literary training and small powers of expression. Teachers have a difficult task in explaining the characters of rocks and minerals to pupils who have no knowledge whatever of the elements of chemistry and physics. But it is evident that effort on the part of the teachers and interest on the part of the students have not been lacking. The percentage of Failures is slightly greater than last year, but the proportion of First to Second Class is about the same. Q. 1. Explain the terms Volcanic and Plutonic, as applied to Igneous

rocks, and give an example of (a) a Vitreous Volcanic rock, (b) a Clastic Volcanic rock, (c) a Basic Plutonic rock, (d) an Acid

Volcanic rock. This question is fairly well answered, the distinction between Plutonic and Volcanic rocks being clearly understood. The choice of examples is not, however, equally satisfactory, and many are puzzled to name a Clastic Volcanic rock. Q. 2. State the chemical composition of (a) the Felspars, (6) the

Hornblendes and Augites. Name rocks in which the following minerals occur as essential constituents :-(c) Orthoclase Felspar,

(d) Labradorite, (e) Common Augite, (1) Common Hornblende. While most of the candidates show a knowledge of the composition of the Felspars, far less acquaintance with the composition of the Ferromagnesian Silicates is displayed. The selection of examples of rocks was, on the whole, satisfactory. Q. 3. Describe the structures found in the following varieties of

Limestone :-(a) Oolite, (6) Chalk, (c) Travertine, (d) Stalactite,

(e) Crystalline Limestone. The chief difficulties which the candidates experience are in describing the structure of Travertine and Crystalline Limestone. The descriptions of Chalk and Ooļite are often very good indeed.

Q. 4. Strata of Lias and Oolite, with a dip of about 30°, are found

covered unconformably by horizontal Cretaceous Strata. Draw

a section to illustrate these relations. The attempts at section-drawing are often very crude and incomplete. There is in many cases no attempt to indicate the different mineral characters of the beds by the use of conventional shading. It would evidently be of great advantage to the pupils if the teachers made a point of seeing that their own blackboard drawings are not of too sketchy a character, and that the pupils are given some practice in section-drawing. Some candidates show Oolite and Lias beds alternating with one another repeatedly. Q. 5. Represent, in a diagrammatic section, the escarpment formed in a bed of limestone

resting on clay, with an outlier of the limestone outside the escarpment. The chief error in the drawing of this section is a failure to indicate that the outlier is really part of the same limestone bed that forms the escarpment. In a few cases, where the outlier is represented at a much lower level than the escarpment, a fault is given to account for the position of the beds, but in many cases the necessity for showing the cause of such relations is not appreciated. Q. 6. Give an account of the formations known as Wealden and Lower

Greensand and the nature of the fossils found in each of these

formations. The few answers given to this question exhibit little knowledge of the subject. The contrast between a fresh water and a marine fauna and flora is very rarely brought out in the descriptions. Q. 7. Describe the internal structure of (a) a Scoria or “Cinder” Cone,

(6) a Lava Cone, (c) a Composite Volcanic Cone. Your descrip

tions should be accompanied by sketches. While the characters of a Cinder and a Lava Cone are fairly well described and illustrated, many of the candidates fail to realise the distinctive features of a “Composite” Cone. Q. 8. What are the distinctive characters of the structures known as

(a) Stratification, (6) Cleavage, (c) Foliation? In what classes of rocks are these several structures found, and how have they

respectively originated ? Stratification and Cleavage are well understood, though some of the candidates make the mistake of saying that the direction of Cleavage is always at right angles to that of Stratification. About Foliation the ideas of the candidates are much more vague, and some even confound Foliation with Folding.

STAGE 2 Results : 1st Class, 45; 2nd Class, 73; Failed, 50 ; Total, 168. There is a marked increase in the number of students in this stage as compared with last year, which is not accompanied by any serious decline in the quality of the answers given to the questions. Some portions of the subject, however, do not appear to have received adequate attention from teachers. Q. 21. Name the six chemical elements which occur in the greatest abund

ance in the Earth's Crust, and six which occur most commonly in Meteorites. Point out the differences in the proportions of the

several elements in the Crust of the Earth and in Meteorites. The subject of this question does not appear to have been well taught. Less than half the candidates select the question, and of these the majority are only acquainted with the six most common elements in the Earth's Crust. Many give oxygen and silicon as the predominating elements in Meteorites, failing to refer to iron and nickel ; while very few bring out clearly the unoxidized nature of the materials as the characteristic feature of Meteorites.

« AnteriorContinuar »