Now Ready. Globe 8vo. Price 4s. 6d.

Physiography

for Advanced Students

BY

A. T. SIMMONS, B.Sc. (LOND.)

ASSOCIATE OF THE ROYAL COLLEGE OF SCIENCE, LONDON

Adapted to the Advanced Stage of the South Kensington Syllabus

Chapter 1. Matter. 2. Work and Energy. 3. Heat and Temperature. 4. Waves in Water, Air, and the Ether. 5. The Atmosphere and Atmospheric Movements. 6. Atmospheric Phenomena in Relation to Climate.

7. Seas and Lakes. 8. Seas (continued)—The Tides. 9. The Earth's Crust ---Rock-forming Minerals. 10. The Earth's Crust-Rocks and their Classification. II. The Earth's Crust-Phenomena connected with the Internal Heat of the Earth. 12. The Earth's Crust-Movements in the Earth's Crust and some of their Results. 13. The Universe-Celestial Co-ordinates, and how they are affected by the Earth's Movements. 14. The Universe -The Law of Gravity in the Solar System. 15. The Universe-Physical Features of the Sun and Moon. 16. The Universe-The Terrestrial Planets and their Moons. 17. The Universe-The Major Planets and their Moons, Comets, and Meteorites. 18. The Universe -The Stars: their Magnitudes and Proper Motions. 19. The Universe-Double Stars, Clusters, and Nebulæ. 20. The Universe-Celestial Measurements. 21. Terrestrial Magnetism. INDEX.

PRESS OPINIONS

Scotsman- Rich in illustrations and in references to deeper authorities, it provides a book suitable especially to students following the syllabus of the Science and Art department, but serviceable to all,"

School Guardian-"The book is an excellent example of a class-book thoroughly up to date."

Nature-"We believe the book will admirably supply the need which must have been felt by teachers and students under the new conditions created by the revised syllabus. In conjunction with the volume to which it is a supplement, it will also provide the general reader with a comprehensive view of the earth and its relation to other bodies in space. "

Educational News-"No better book on the subject has hitherto come under our notice, and we recommend it with full confidence."

Educational Review-"The exposition is lucid, the matter full, accurate, and up to date. It is altogether an excellent text-book."

J

Pupil Teacher-"It is impossible to speak too highly of this excellent work. We cordially recommend the work, as a continuation of Physiograpy for Beginners, as being admirably suited for advanced pupils studying for the Science and Art Department Syllabus."

Educational Times-"We can congratulate the author on his clear descriptions and on the admirable series of illustrations which he has brought together from so many sources.'

Speaker-"The essential features of the plan of the earlier book are here presented-precise instructions for simple experiments, summaries of chapters, and questions. The book will be acceptable to the general reader, who, as well as the science student, will find plenty of interesting illustrations. As the book is thorough, it is well worth a place in the science library of Messrs. Macmillan."

XII

THE EARTH'S CRUST

271

whole melts, its valley is seen to have assumed the form of smooth undulating prominences, in appearance not unlike the back of dolphins as they appear at the surface of the water in which they are rolling. These rounded mounds are called roches moutonnées, from a similar likeness they exhibit to the backs of sheep.

The water formed from the local melting of a glacier collects on the surface and often finds its way down one of the numerous crevasses, carrying with it a considerable quantity of the moraine detritus. This water finally gets under the glacier, and in many cases, by the help of the stones it carries with it, erodes a kind of pot-hole, which is in some places spoken of as

a giant's kettle. As was pointed out in describing the same sort of work in the case of rivers, the largest amount of erosion will be effected in those cases where the rocks are soft. It is sometimes indeed sufficiently extensive to form considerable hollows, which on the retirement of the glacier often becomes filled with water, forming tarns or lakes (p. 150).

Results of Glacial Action.-The student will readily perceive that it is quite possible to tell where glaciers have been from the permanent record they leave behind. We can summarise the occurrences, the existence of which in any country can be taken as proof of the previous existence of glaciers.

364 PHYSIOGRAPHY FOR ADVANCED STUDENTS CHAP.

Physical Features of Mars.-The planet Mars generally presents the aspect of a ruddy disc, which is, as before remarked,

FIG. 162.-Mars on August 29, 1894, showing the Planet in the Gibbous phase. (From a Drawing by Mr. Percival Lowell in The Astrophysical Journal, No. 128).

gibbous in form at stated times. Its surface markings can be distinctly made out with a telescope having a four- or five-inch

FIG. 163. The Planet Mars, as drawn by Prof. James E. Keeler on August 17. 1892. The South Polar Cap is shown in each of the Drawings.

Fcap. 8vo. 4s. 6d. (Questions on the same, 1s. 6d.)

ELEMENTARY LESSONS

IN

PHYSICAL GEOGRAPHY

BY

SIR ARCHIBALD GEIKIE, F.R.S.

[First Edition 1877; reprinted 1878, 1880, 1882 (2), 1883 (2), 1884. Second Edition 1884; reprinted 1886, 1887, 1889, 1890, 1892, 1894, 1897 (2), 1898 (2), 1899.]

London

MACMILLAN AND CO., LIMITED

NEW YORK: THE MACMILLAN COMPANY

Academy-"The language is always simple and clear, and the descriptions of the various phenomena are no less vivid than interesting; the lessons are never dull, never wearisome, and they can scarcely fail to make the study of Physical Geography popular wherever they are used."