SCIENCE- G OSSIP. 



277 



treated in detail and in a clear and vigorous manner. 

 Considering that this work is the translation of ithe 

 1896 German edition, the matter in one or two 

 places might have been a little more in accord with 

 present knowledge. Taking only, one example we 

 may instance the liquefaction of gases on pp. 227- 

 231. Nothing is apparently said of the valuable 



Fig. 199. Enlarged View of Index. 

 (Heat for Advanced Students.) 



work of Olskewski, Dewar, Linde, or Hampson ; in 

 fact the regenerative processes of liquefaction are not 

 mentioned at all. Nevertheless the book may prove 

 a useful one to general students of physics. —J. Q. 



Botany for Beginners. By Ernest Evans. 

 vi + 290 pp., 8 in. x 6 in., illustrated by 271 figures. 

 (London and New York : Macmillan & Co., 1899.) 

 2s. 6d. 



This little work has the desirable object of pro- 

 viding students with a means of obtaining practical 

 knowledge in the study of plants. Though only 

 intended as a guide to those commencing work, the 

 carefully drawn illustrations, prepared by Mr. W. E. 

 Holt, and the excellent matter in the text, make it a 

 useful text-book to all, even advanced students of 

 this fascinating study. The author, who is a natural 

 science master of the technical schools at Burnley, 

 commences with a study of the morphology of plants, 

 proceeding to the anatomy, thence to the analysis of 

 sections, the histology of the cells, tissues, and roots, 

 the physiology of growth and movement, classification 

 and plant description. A good index further enhances 

 the value of this small text-book. 



The Birds of Eastern North America. Water 

 Birds. Part I. By Charles B. Cory. ix+ 143 pp. 

 1 1 in. x 9 in., with numerous illustrations. (Chicago : 

 Field Columbian Museum, 1899.) 



This is the first part of a series of beautifully 

 illustrated works on the birds known to occur east of 

 the ninetieth meridian. This part deals only with 

 the water birds, but it is proposed to issue a series of 

 these "keys," in which the species are grouped 

 according to size, not in genera, as is usual. It is 

 believed this plan will enable a novice to accurately 

 identify any of the birds. All measurements are 

 given in inches and fractions of inches. The illustra- 

 tions, which are well produced, are many in number, 

 and include many well known in this country. 



GEOLOGY 



CONDUCTED BV EDWARD A. MARTIN, F.G.S. 



Striae as Evidence ov Ice Action. — Mr. E. A. 

 Martin, under the head of striae and ice action in a 

 recent issue of Science-Gossip, certainly shows that 

 great care should be exercised in the identification of 

 glacial striations. There is no doubt that, under 

 certain conditions, features greatly resembling glacial 

 striae may be produced on solid rock surfaces by 

 other agency than that of ice action, but such instances 

 are few and far between, and are the exception rather 

 than the rule. I of course refer now to whole sur- 

 faces of rock being striated, not odd scratches, such 

 as might be produced with a pair of hobnailed boots. 

 Yet is there not a possible chance of too much being 

 made of these non-glacial striae, and a danger of 

 getting to the very opposite extreme ? I think there 

 is, and the note from the pen of Dr. P. Q. Keegan 

 in your December issue (p. 222) has been written, I 

 fear, whilst enthusiastic on the subject. Dr. Keegan 

 states that striae "are evidence of nothing at all, 

 except the inroads of the weather, lichens, etc." 

 This is all very well for a scratch or two of limited 

 dimensions upon a rock, but will not account for the 

 striae covering yards and yards of rock, we might 

 almost say acres, which exist in certain parts of 

 Britain. Several of these genuine glacial striations 

 are many yards in length, and in some cases their 

 width and depth can be measured by inches. Further, 

 the general direction of the striae usually agrees 

 with the a priori view of the direction of the 

 glacier. It agrees with the slope of the valley, and 

 is in rough parallel with its sides. Where lateral 

 moraines exist these also coincide with the striae, whilst 

 the transportation of boulders, their orientation, and 

 numerous other indications strongly support the 

 theory that the striae were made by "a monster glacier 

 filling up the valley," and by that only. No amount 

 of lichens or inroads of the weather could possibly 

 produce such phenomena. I regret I am not per- 

 sonally acquainted with the " grand rocks edging the 

 valley where the Derwentwater reposes," but from 

 numerous excursions made into the neighbourhood of 

 the lake district, I have no hesitation in saying that 

 they are in all probability genuine glaciated rocks, 

 and that Mr. Ward was correct in his description. 

 We have the most unmistakable evidence that the 

 whole of the lake district was extensively glaciated. 

 The striae on a single surface of rock must be consi- 

 dered in connection with the whole glacial phenomena 

 of the neighbourhood, and the striae and other glacial 

 features will be found to agree with rather than be 

 in conflict with each other. The recent researches 

 of Mr. Joseph Lomas on glacial striae, published in 

 the " Proceedings of the Liverpool Geological As- 

 sociation " and in the *'. Racialists' Magazine," are 

 convincing. 



Geological Exchange Meeting. — The next 

 meeting will take place at Science-Gossip offices 

 on Wednesday, February 7, from 5.15 P.M. to 7 P.M. 

 The success hitherto attending these meetings has 

 not been so great as could be desired, and it is 

 hoped that geologists will be present in greater 

 numbers with their specimens. 



