204 



SCIENCE. 



[Vol. VII., No. 163 



practical manual of ' Astronomical work for 

 amateurs,' the aim of which will be to help the 

 possessors of limited instrumental means to turn 

 their attention to astronomical researches of real 

 scientific utility, special attention being directed 

 to the comparatively new fields of spectroscopy 

 and celestial photography. The book will be pub- 

 lished by Messrs. Longmans & Co. Mr. Oliver, 

 in the mean time, invites suggestions from prac- 

 tical workers, which may be sent to him at Loch- 

 winnoch, Scotland. 



— ' The weather journal' (Cincinnati, S. S. Bass- 

 ler) is the title of a new weekly paper to be de- 

 voted to the general meteorology of the eastern 

 United States, illustrated by tri-daily charts of 

 the movements of the atmosphere and the distri- 

 bution of atmospheric pressure and temperature. 



— The wealth and richness of the illustrations 

 of Mr. I. C. Russell's 'Recent glaciers of the 

 United States' (Fifth annual report, U. S. geol. 

 surv.) would alone give his work value, but they 

 serve only to embellish what without them is a 

 very interesting treatise. Some of the engravings 

 of Mounts Shasta and Dana are especially strik- 

 ing. One is surprised to learn of the extent to 

 which glaciers occur in the United States through- 

 out the northern Sierra Nevada and Rocky moun- 

 tains, while in the Cascade Mountains are numer- 

 ous ones, flowing through narrow defiles and 

 over precipices, and, as the author says, by no 

 means unworthy of comparison with the ice-fields 

 of Switzerland and Scandinavia. In Alaska the 

 catalogue is still further extended, embracing 

 numerous examples of alpine glaciers as magnifi- 

 cent as any in the world. 



— Professor Chamberlin's paper, in the ' Fifth 

 annual report of the U. S. geological survey,' on 

 artesian wells, is one that cannot help but be of 

 practical value. It was the author's aim to in- 

 clude in convenient form such information rela- 

 tive to the qualifying conditions of artesian wells 

 as may be capable of brief, general statement, 

 and may seem to be serviceable alike to citizen, 

 driller, and geologist ; and he has evidently suc- 

 ceeded. 



— Some novel and interesting applications of 

 instantaneous photography to the study of the 

 movements of the heart and intestines have re- 

 cently been made by Dr. W. G. Thompson. 

 Photographs of rabbits', pigeons', cats', and frogs' 

 hearts were made in different stages of systole and 

 diastole, showing the action more clearly and ac- 

 curately than is possible by other methods. In 

 addition to the value of such in physiological 

 teaching, the most practical application of the 



method will be the illustration of the changes in 

 the form of the heart and intestines produced by 

 drugs ; and the author believes the process may 

 be further extended to the study of the contrac- 

 tions of the stomach, bladder, and diaphragm, 

 and other viscera. 



LETTERS TO THE EDITOR. 



*** Correspondents are requested to be as brief as possible. The 

 writer's name is in all cases required as proof of good faith. 



The trade in spurious Mexican antiquities. 



A note supplementary to my paper on Mexican 

 pottery, published in your issue of Feb. 19, may be 

 of interest to a number of readers. 



The fradulent specimens referred to reach this 

 country in two ways, — through the agency of 

 travellers who purchased them in Mexico, and 

 through traders who ship them to New York in 

 large lots. From recent observations I have reached 

 the conclusion that there are now in the collections 

 of this country specimens valued at many thousands 

 of dollars, yet which, since they are fraudulent and 

 in every way vicious, are not worth the trouble of 

 breaking up and casting away. Peru is hardly less 

 fully represented, as the factories in that country 

 have been at work for a number of years. 



The detection of modern work is in many cases a 

 difficult matter, but in others a decision is easily 

 reached. With reference to the Peruvian frauds, it 

 may be taken for granted that new-looking speci- 

 mens are new, and, besides, that many old-appear- 

 ing- pieces are new. If exterior appearances are not 

 sufficient to satisfy the collector as to the age of 

 suspected pieces, let him break some very narrow- 

 necked' vessel, either of the light terra- cotta colored or 

 of the black ware, and he will probably find that the 

 inside is innocent of any stain of age. 



I may add that objects of stone from both of these 

 countries need careful inspection. 



W. H. Holmes. 



Washington, D.C. 



The anachronisms of pictures. 



The articles of Professors Holder and Lockwood 

 (Science, vii. 220 and 242) remind me of what I saw 

 many years ago in one of the ladies' magazines, — a 

 picture of the embarkation of the Pilgrims from 

 Delft Haven, with steamships at anchor in the bay. 

 An enterprising artist ! — only about two hundred 

 years ahead of his time, and the picture probably 

 ' drawn by our artist on the spot.' C. G. 



Homer, N.Y. 



Is the dodo an extinct bird ? 



It is very improbable that the dodo has been found 

 in the Samoan Islands, alive or fossil. It inhabited 

 the islands of Mauritius and Bourbon in the Indian 

 Ocean. The bird alluded to by Mr. Hopkins as still 

 living in Samoa is probably the Didunculus, a speci- 

 men of which I well remember in the collection of 

 Sir William Jardine, the famous ornithologist. Sir 

 William thought the Didunculus was allied to the 

 dodo and the pigeon. W. S. Symonds. 



The camp, Sunningdale, Feb. 29. 



