204 THE GENESIS OF SCIENCE. 



the phenomena of the seasons, and the chief events from 

 time to time occurring, have been used by early and un 

 civilized races. Among the Egyptians the rising of the 

 Nile served as a mark. The &quot;New Zealanders were found 

 to begin their year from the reappearance of the Pleiades 

 above the sea. One of the uses ascribed to birds, by the 

 Greeks, was to indicate the seasons by their migrations. 

 Barrow describes the aboriginal Hottentot as denoting 

 periods by the number of moons before or after the ripen 

 ing of one of his chief articles of food. He further states 

 that the Kaffir chronology is kept by the moon, and is 

 registered by notches on sticks the death of a favourite 

 chief, or the gaining of a victory, serving for a new era. 

 By which last fact, we are at once reminded that in early 

 history, events are commonly recorded as occurring in cer 

 tain reigns, and in ceilain years of certain reigns : a proceed 

 ing which practically made a king s reign a measure of 

 duration. 



And, as further illustrating the tendency to divide time 

 by natural phenomena and natural events, it may be no 

 ticed that even by our own peasantry the definite divisions 

 of months and years are but little used ; and that they 

 habitually refer to occurrences as &quot; before sheep-shearing,&quot; 

 or &quot; after harvest,&quot; or &quot; about the time when the squire 

 died.&quot; It is manifest, therefore, that the more or less 

 equal periods perceived in Nature gave the first units of 

 measure for time ; as did Nature s more or less equal 

 lengths and weights give the first units of measure for space 

 and force. 



It remains only to observe, as further illustrating the 

 evolution of quantitative ideas after this manner, that 

 measures of value were similarly derived. Barter, in one 

 form or other, is found among all but the very lowest hu 

 man races. It is obviously based upon the notion of 

 equality of worth. And as it gradually merges into trade 



