930 



SCIENCE 



[N. S. Vol. XLIII. No. 1122 



Dr. Stejneger has called my attention to the 

 fact that the specific name under -which Mr. 

 Doolittle's specimen was reported should prop- 

 erly have been written Ambystoma maculatum 

 instead of Ambystoma punctatum, as shown by 

 him in 1902.« 



M. W. Lyon, Jr. 



George Washington University 



CENTIGRADE VERSUS FAHRENHEIT 



In the article by A. H. Sabin, appearing in 

 the May 5 issue of Science, entitled " The 

 Centigrade Thermometer," were expressed the 

 sentiments of many scientific workers, who 

 have had no other method of voicing their op- 

 position to his scheme accorded to them by 

 Representative Johnson, than through articles 

 in various publications. 



In the judgment of the writer the set of 

 questions submitted to him by Mr. Johnson 

 should have been so constituted as to have per- 

 mitted the views of the opposition to have 

 been presented. 



The inconvenience of the Fahrenheit scale is 

 not apparent to the writer. 



The number denoting the temperature range 

 between the freezing point (32°) and the boil- 

 ing point (212°) of water, being 180 is divisible 

 without a remainder by 1, 2, 3, 4, 5, 6, 9 

 and 10; while the number for the Centigrade 

 scale denoting the same range, namely 100, is 

 divisible by only 1, 2, 4, 5 and 10 without a 

 remainder; or three less divisors, tending to 

 arouse the suspicion that the Fahrenheit scale 

 is more " rational " than the Centigrade scale. 



It is the opinion of the writer that such a 

 change as is contemplated b.y Mr. Johnson 

 would not only be idiotic, but a most undesir- 

 able blow at educational efficiency^ the most 

 important factor entering into the life of every 

 human individual. 



F. E. Austin 



Hanover, N. H. 



safety razor blades for hand 

 sectioning 



If there are still any botanists so old-fash- 

 ioned as to cut sections by hand, they may be 



eProo. Biol. Soc. Wash., Vol. 15, pp. 239-240, 

 December 16, 1902. 



glad to know, both for themselves and for their 

 students, of the convenience and cheapness of 

 the razor I am now using. 



The present stropping handle of the Gem 

 Safety Razor is the holder, the Gem Damascene 

 the blade. The total cost is about fifteen cents. 

 The blades, when dull, can be replaced for five 

 cents, but in the stropping holder they may 

 very easily be kept sharp. 



I find this thin, keen, easily stropped razor 

 admirably suited to light work. I am not sure 

 that it would be heavy enough to cut hard 

 wood satisfactorily, but it sections leaves, stems 

 and roots, even of considerable size and hard- 

 ness. I am so pleased with the result that I 

 wish to share it. 



George J. Peirce 



Botanical Laboratory, 

 Stanford University, 

 California 



SCIENTIFIC BOOKS 



Ptolemy's Catalogue of Stars. A Revision of 

 the Almagest. By C. H. F. Peters and E. 

 B. Knobel. Carnegie Institution of Wash- 

 ington, 1915. 



It will give pleasure to astronomers to have 

 this long and careful work on the collation of 

 existing manuscript copies of the " Almagest " 

 so well presented in published form. It is the 

 oldest known catalogue of measured star 

 places, and while observers of this day can re- 

 ceive little assistance in comparing those 

 rough measurements with modern positions, 

 the catalogue will still exhibit the changes in 

 the heavens due to precession, and it serves .is 

 a record of the unchanging character of the 

 distribution of the bright stars. 



No original copy of Ptolemy's " Almagest " 

 is in existence, so far as known, and the 

 earliest manuscripts thus far found were made 

 eight or nine centuries after the epoch of the 

 catalogue. Both Greek and Arabic manu- 

 scripts are among the early transcripts; the 

 Latin copies were translations of either one 

 of these. In the transcriptions many errors 

 were made, due in part to the ignorance of 

 astronomical science on the part of copyists, 

 and to the difficulties of translating the nu- 



