I 



Dr. Andrew Fyfe on the Comparative Value, fyc 157 



The existence of this superstition, joined to the circumstance of 



the year terminating at a time when the recession of the sun was 



greatest, may have invested this period with so much importance 

 as to make it a chronological era, from whence to date the years 

 anew. However this may be. the conjunctions here noticecToffer 

 a better explanation of the singular selection of fifty-two years 

 for the cycle, than is furnished by any analysis of the multiples 

 of which that number is made up. It is not impossible however, 

 that the further circumstance that the sacred numbers four and 

 thirteen were multiples of fifty-two, may have had a secondary 

 weight in the length of the cycle. 



Passing by this question, we find that the discovery of the 

 missing date of the winter solstice completes the circle of the 

 sun's principal positions, as engraved upon the great Calendar 



Stone — -a monument which still furnishes an interesting object 



of study, and the full understanding of which would no doubt 

 tend greatly to increase our estimate of the astronomical knowl- 

 edge and the ingenuity of the aboriginal Mexicans. 



Note. — The apprehension of the extinguishment of the sun, 

 at the winter solstice, is mentioned by Humboldt as affording a 

 striking instance of the analogy which existed between the super- 

 stitions and religions observances of the ancient Mexicans, and the 

 primitive nations of the old world. " When the Egyptians," says 

 Achilles Tat i us, " saw the snn descend from the Crab towards 

 Capricorn, and the days gradually diminish, they were accustom- 

 ed to sorrow from the apprehension that the sun was to abandon 

 them entirely. This Epocha coincided with the festival of Isis : 

 but when the orb began to reappear, and the days grew longer, 

 they robed themselves in white garments, and crowned them- 

 selves with ftoweis."— Humboldt's Res., vol. 1, p. 383. 



Art. XI. 

 for the purpose of 



of different Kinds of 



erto 



for ascertaining the Value of the Gases they afford; 

 by Andrew Fyfe, M.D., F.R.S.E , F.R.S.S.A., Professor of 

 Chemistry, King's College University, Aberdeen, &c. Read 

 before the Royal Scottish Society of Arts. 



(Continued from page 86.) 



In the preceding part of this paper, I have shewn that gases 

 from different coals not only require different times for the con- 

 sumption of equal volumes, but that for these consumptions dif- 

 ferent pressures are necessary. It is of importance, therefore, to 

 ascertain whether the consumption and the pressure bear the same 

 ratio to each other when different gases are used, that they do 



