932 



SCIENCE 



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



magnitudes are always those derived by Dr. 

 Peters; and the identification with modern 

 star designation, a tabulation of the errors 

 found, and the comparison with the Harvard 

 photometric magnitudes have been added. 

 The fact that Ptolemy lived at Alexandria, 

 four degrees south of Rhodes, the site of 

 Hipparchus's observations, and yet did not in- 

 clude any more southern stars than did the 

 latter, is one point of evidence against a new 

 series of observations by Ptolemy. Hipparchus 

 is supposed to have observed 1,080 stars. The 

 work of identification involved the reduction 

 of modern star places back to the respective 

 epochs of the old observations, and, with this, 

 the computation of the probable errors of the 

 old measures. These had been recorded in 

 fractions of a degree, and the fact that much 

 confusion arose in transcribing these fractions 

 in the Greek has added to the uncertainty of 

 some of the identifications. Many of the 

 manuscripts in existence are evidently copied 

 from some particular original, and the errors 

 of that original would be reproduced, in addi- 

 tion to new mistakes of transcription. 



After the death of Dr. Peters, in 1890, the 

 collection of material made by him was sent 

 to Mr. Knobel, who has enlisted the support of 

 astronomers and public-spirited men in having 

 the results of their joint labors properly recog- 

 nized by the publication in permanent form. 

 The volume contains an excellent portrait of 

 Dr. Peters, and some photographic reproduc- 

 tions of the pages of the two oldest copies of 

 the " Almagest." 



E. H. Tucker 



Lick Observatory, 

 March 21, 1916 



Flora of the Northwest Coast. By Charles 

 V. Piper and E. Kent Beattie. Published 

 by the authors, Washington, D. C, Novem- 

 ber 10, 1915. Pp. xiii + 418. Price $1.50. 

 Students of the flora of western North 

 America will welcome Piper and Beattie'a 

 " Plora of the Northwest Coast." The authors 

 are to be congratulated for bringing to fruition 

 the labors of their earlier years for the botany 

 and botanical education on the Pacific coast. 



Their new work wiU contribute greatly to the 

 knowledge of the plant life in the northwest 

 and, as they themselves express the hope, will 

 " stimulate a greater activity and interest in 

 the flora." 



The area covered by the manual is that 

 lying west of the summit of the Cascade 

 Mountains from the headwaters of the Willa- 

 mette River in southern Oregon to the 49th 

 parallel of latitude. This is a natural geo- 

 graphic region characterized by its magnifi- 

 cent coniferous forests which form the domi- 

 nating plant formations over nearly the en- 

 tire area below 5,000 feet altitude. " The only 

 break in this coniferous cover consisted orig- 

 inally of a series of prairies extending from 

 the Upper Willamette Valley northward to 

 Vancouver Island. North of the head of 

 Puget Sound, however, the prairies are small 

 and limited in the main to the extremities of 

 points and portions of the islands in the 

 Sound." 



In a forested region such as the northwest 

 the lignescent flora naturally attracts atten- 

 tion, and it is interesting to note that, al- 

 though the forests are largely composed of a 

 few species of conifers, there is a compara- 

 tively large variety of trees and shrubs, ap- 

 proximately 9J per cent, of the total flora. Of 

 the 155 species of woody plants described, 47 

 are trees, 105 shrubs and 3 woody climbers. 

 The genera with more than two species of trees 

 are, Pinus 6, Abies 6, Balix 5, and Acer 3. 

 The genera with five or more species of shrubs 

 are, Salix 14, Ribes 10, Spiraea 5, Bubus 6, 

 Ceanothus 6, and Vaccinium 9. 



A summary of the fiora is given in a table, 

 from which we learn that there are described, 

 100 families, 550 genera and 1,617 species and 

 subspecies, distributed as follows : Pteridophyta 

 7 families, 22 genera and 61 species; Gymno- 

 sperms 2 families, 10 genera and 22 species; 

 Monocotyledons 15 families. 111 genera and 

 412 species ; Dicotyledons 76 families, 407 gen- 

 era and 1,122 species. The composition of the 

 flora may be brought out a little more fully by 

 listing a few of the prominent families and 

 genera. The families containing more than 60 

 species are : Poacese 46 genera and 116 species. 



