2 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



forms. The literature of this subject has, in fact, grown to 

 be quite voluminous, since the first papers that were publish- 

 ed by Moseley and Naumann, thirty years ago. The conch 

 shells, according to both these authors, are based upon a 

 spiral curve that is sensibly identical with the so-called log- 

 arithmic spiral ; but, subsequently, Naumann adopted the 

 theory that the spiral was one peculiar to the animal build- 

 ing the shell, .and ho therefore proposed the name of the 

 concho-spiral. The subject has lately been investigated by 

 Grabau, and apparently with very great ability. He states 

 that he has sought to determine whether it were possible, if 

 not in theory, at least in practice, to confound the concho 

 spiral and the logarithmic spiral ; and then again, to deter- 

 mine whether, allowing the possibility, some of the observers 

 had not actually erred in this very direction. His very 

 thorough mathematical investigation, and equally laborious 

 mathematical computations, lead to the conclusion that, from 

 the totality of Naumann's calculations, an unprejudiced critic 

 must conclude in favor of the reality of the concho spiral, so 

 far, at least, as this is possible from the diameters and meas- 

 ures given by him ; and one can but suspect that, if not all 

 conchs, at least some, and decidedly the most, have actually 

 built upon the concho spiral, and that only the fact that the 

 asymptotic circle of this curve is frequently too small has 

 favored the assumption that, in these cases, the shell has fol- 

 lowed the logarithmic spiral. Inaugural Dissertation, JLcip- 

 sic, 1872. 



THE LENGTH OF THE EGYPTIAN CUBIT. 



The earnest labors and writings of Professor Smythe, As- 

 tronomer Royal for Scotland, have succeeded in drawing at- 

 tention to the importance of the accurate determination of 

 the value of the units of length, weight, and volume that were 

 formerly in use in Egypt. There can at last be no doubt 

 but that the measures in use by us in modern times, except- 

 ing of course the French metric system, are a direct inherit- 

 ance from the days of the early Egyptians ; that, in fact, the 

 measures used by the Hebrews were identical with those of 

 Egypt, and that there is a remarkable similarity even between 

 the ancient measures of China, Assyria, and Egypt. Although 

 much has been written to controvert the positions taken by 



