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 Člastic Volcanic rock.

Q. 2. State the chemical composition of (a) the Felspars, (b) the Hornblendes and Augites. Name rocks in which the following minerals occur as essential constituents :-(c) Orthoclase Felspar, (d) Labradorite, (e) Common Augite, () 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, (b) 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 Oolite 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, (b) a Lava Cone, (c) a Composite Volcanic Cone. Your descriptions 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, (b) 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 abundance 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.

Q. 22. Describe the principal species of Mica which occur as rock constituents, indicating the particular class of rocks in which each of these species occurs.

Most of the candidates are acquainted with the chief characters of Muscovite and Biotite, but do not recognize the existence of any other kinds of Mica. Instead of stating the class of rocks in which the several species of Mica occur, they give a list of names of micaceous rocks.

Q. 23. State the mineralogical constitution and the structure of common basalt, and indicate the relations to basalt of the following rocks(a) Tachylyte; () Gabbro; (c) Variolite; (d) Amygdaloidal Melaphyre.

This question, which is selected by a considerable majority of the candidates, is, on the whole, very well answered. Among the mineral constituents of Basalt, olivine, magnetite and glass are frequently omitted. Very few appear to be acquainted with Variolite, and the nature and mode of origin of Amygdaloids is not well understood.

Q. 24. Give an account of the nature and origin of (a) Slickensides, (Crushed and impressed pebbles, (c) Friction Breccias, (d) Mylonites.

Also answered by a majority of the candidates. A considerable amount of knowledge is shown concerning Slickensides and Friction Breccias; but the statements about Crushed and Impressed Pebbles are evidently guesses, based on the name and its association, while little knowledge is shown concerning Mylonites.

Q. 25. Describe the composition and modes of occurrence of Septaria, and explain their origin.

This question, which is selected by only a few of the candidates, is by no means so well answered as might have been anticipated.

Q. 26. Draw a section showing beds of limestone and slate traversed by reversed step-faults and overlain by false-bedded sands.

Selected by nearly all the candidates, and fairly good drawings are given. In some cases, however, the diagram is incomplete, the most prevalent error being a failure to make clear the unconformable relations of the false-bedded sands to the faulted strata below.

Q. 27. Give an account of the nature and origin of different varieties of Volcanic Bombs. What are Pseudo-volcanic Bombs, and how

are they formed?

That this subject is still imperfectly taught is shown by the circumstance that very few of the candidates attempted an answer to the question. Of this small number scarcely any show any real knowledge concerning the nature and origin of Volcanic Bombs and the objects which simulate them. Q. 28. Describe the composition, structure and relations of the rock called Troctolite ("Forellenstein ").

The half a dozen candidates who alone selected this question give good answers to it-some of them excellent ones. But it is evident that practical petrological teaching at this advanced stage is not as good as could be desired.

Q. 29. Describe the relations of the Coal Measures in the Midland Coalfields of England to the strata which lie above and below them respectively.

Many

This question when selected is not very satisfactorily answered. of the candidates appear to think that a general statement of the carboniferous succession is all that is required. At present there does not seem to be much geological teaching with an economic bearing.

Q. 30. Give an account of the nature and mode of formation of the chief deposits of iron-ore which are of economic importance.

It is evident that the teaching had not covered the subject of this question. The answers are few and very imperfect in almost all cases,

Q. 31. Describe, with the aid of sketches, the jointing of limestone rocks and explain how the operation of quarrying is facilitated by the presence of joints.

The subject of joints had clearly been well taught and as a rule their economic value and importance are recognised. The one point upon which there is some ambiguity is the necessity of bedding planes as well as of two sets of joint planes for the quarrying of cuboidal blocks.

STAGE 3.

Results 1st Class, 18; 2nd Class, 13; Failed, 9; Total, 40.

In this stage there is not only a marked increase in the number of candidates, but a very considerable improvement is manifested in the character of the answers. Many of the descriptions given of the Radiolarian Ooze are very full and complete, the most serious error (which is only seen in a few cases) is the failure to recognize the siliceous character of the skeletons of Radiolaria. It is a strange circumstance that some among the candidates, who give fair descriptions of the Radiolarian Cherts, argue that the occurrence of these among upraised stratified rocks must be regarded as an evidence in favour of the permanence of Ocean-basins. In connection with Question 42, it is a very gratifying circumstance to find that some of the candidates have evidently visited the dry valleys of Yorkshire and Derbyshire, while one of them has evidently made a personal examination of the Mole Valley. The accounts given of the appearances witnessed in these valleys, and of the methods of experimenting with a view to determine the actual courses of the underground streams, are in every way admirable. It is not apparent from the papers whether these geological excursions had been made under the guidance and direction of the teacher, or had been undertaken by the students upon their own initiative. In the Question on Coral Reefs (43) a good deal of ignorance was shown concerning the important part played by Calcareous Algae ("Nullipores"), Foraminifera, and other organisms in forming reefs. This, however, is probably due to the imperfect accounts given in most of the text-books. Neither in the answers to Question 44 (Spherulites and Lithophyses), nor in that to Question 46 (Peridotites), is a very satisfactory knowledge of Petrology shown. Probably few of the schools are provided with the microscopes and specimens necessary for teaching the subject practically. Side by side with several very weak answers to Question 45 (on a comparison of the Faunas of the Crag and Glacial periods), there were two or three very full and complete ones, showing much knowledge and intelligence on the part of the candidates. On the whole, we consider the results in this stage to compare very favourably with those of last year. They afford evidence of excellent and, we think we may add, enthusiastic teaching, and the way in which out-of-door work has been undertaken is most praiseworthy.

HONOURS.

Results: 1st Class, 5; 2nd Class, 6; Failed, 1; Total, 12.

There is the same number of Honours papers in Geology this year as there was in 1905; but the Failures are fewer and the First Classes more numerous. There is a very considerable improvement in the quality of the answers, especially to the Paleontological questions. It was an unfortunate circumstance that one of the candidates, who had to be placed in the Second Class, after giving excellent answers to three questions, stated that he was unable to attempt a fourth for want of time. His failure to complete the paper was undoubtedly owing to the undue amount of time which he had devoted to the three questions answered. There is evidence in nearly all the papers sent in of much careful reading and study, and the papers certainly reach the highest University standard. The greatest weakness is shown in the subjects of Petrology and Stratigraphical Geology. The want of success in Petrology is probably due to insufficient equipment of the schools. The weakness in Stratigraphical

Geology is less easily accounted for, seeing that provision was made for students residing in different areas by giving a choice for description of a Palæozoic, a Mesozoic and a Cainozoic formation. It is surprising to find that few candidates appear to be aware of the fact that Garnets, of several species, form important constituents of some igneous, as well as of many metamorphic rocks.

Report on the Examination in Mineralogy.

There is an increase in the number of papers as compared with 1905. The teaching still seems to be excellent in this subject, the percentage of failures being still very low, though there is a decline in the number obtaining a First Class. The only ground of regret is that the subject is not more generally taught, especially in the mining districts.

Results

STAGE 1.

1st Class, 19; 2nd Class, 24; Failed, 5; Total, 48.

In the increased number of papers in this stage there are very few failures, but the number of First Classes is not quite as high as was the case last year. The great increase is in the number who obtained a Second-Class.

Q. 1. Draw (a) an Octahedron, (b) a Rhomb-dodecahedron, (c) a combination of these two forms. Name a common mineral which is found crystallised in each of these forms.

Of the rather more than half the candidates who attempted this question, the great majority find no difficulty in drawing the Octahedron and the Rhomb-dodecahedron. But a considerable number experience difficulty in representing a combination. Without an opportunity of handling models of crystals, it is to be feared that such difficulty will always be felt. Q. 2. Name (a) a mineral which exhibits Adamantine lustre, (b) one showing Vitreous lustre, (c) one with Metallic lustre, (d) one with Submetallic lustre, (e) one with Earthy lustre. State what is meant by (ƒ) Dichroism, and (g) Trichroism.

Good answers are the rule as far as the first part of the question is concerned, and good selections are made of minerals exhibiting different varieties of lustre. Dichroism and Trichroism are, however, seldom well understood, confusion with particolour, play of colours, and even dimorphism being frequent.

Q. 3. Give the names of the minerals which exhibit magnetic properties, and state how you would test the magnetism of a mineral. This question is only moderately well answered, and very few of the candidates recoguise the existence of "polarity" in magnetic minerals. Q. 4. Calcite and Aragonite are said to be "dimorphous forms of the same chemical compound." Explain what is meant by this

statement.

Most of the candidates appear to understand the term "dimorphism." The difference of crystal form is generally recognised, though often badly expressed, but the difference in other physical properties of Calcite and Aragonite are seldom referred to.

Q. 5. Describe the minerals which are sulphides of iron, lead and zinc, respectively.

Well answered except in certain cases, where neither Marcasite nor Pyrrhotite are enumerated among the iron-sulphides.