R. M. Deeley — Climate and Time. 57 



During the later Cave periods the flake-implements show more 

 skilled workmanship and a greater variety of forms, and this 

 improvement is maintained in the Neolithic age. 



The occurrence, however, in the Chelles and St. Acheul periods of 

 most of the types of flake-implements, such as the grattoir, the 

 racloir, and the knife, points to the fact that early palseolithic man 

 was already acquainted with the patterns and methods of making 

 the flake-implements, hut for unknown reasons he preferred, or was 

 compelled to use, the core-implement. 



Evolution or descent with modification can he traced from some 

 palaeolithic to neolithic types, corresponding with changes of 

 conditions and a gradual advance in civilization. 



Without the aid of geology no precise chronology among cultural 

 stages could be traced ; with its aid, time-relationships can be 

 determined and the several types of flint-implements, instead of 

 of being mere objets de vertu, acquire anew value as " zone-fossils ". 



II. — Climate and Time. 

 By K. M. Deeley, V.P.G.S. 



SIR CHARLES LYELL in his Principles of Geology, published in 

 1834, remarks upon the accumulating proofs that the climate of 

 the earth had undergone great changes in the past, and he 

 endeavoured to show that these changes might have been produced 

 by the varying distribution of sea and land. He says, "But if, 

 instead of vague conjectures as to what might have been the state of 

 the planet at the era of its creation, we fix our thoughts steadily on 

 the connexion at present between climate and the distribution of land 

 and sea; and if we then consider what influence former fluctuations 

 in the physical geography of the earth must have had on superficial 

 temperature, we may perhaps approximate to a true theory." 



The attitude adopted by Lyell may be well illustrated by a few 

 quotations from chapter vii of the above-mentioned work : — 



"The ocean has a tendency to preserve everywhere a mean 

 temperature, which it communicates to the contiguous land, so that 

 it tempers the climate, moderating alike an excess of heat or cold. 

 The elevated land, on the other hand, rising to the colder regions of 

 the atmosphere, becomes a great reservoir of ice and snow, attracts, 

 condenses, and congeals vapour, and communicates its cold to the 

 adjoining country." "Among other influential causes, both of 

 remarkable diversity in the mean annual heat, and of unequal 

 division of heat in the different seasons, are the direction of currents 

 and the accumulation of drifting ice in high latitudes." " If we now 

 proceed to consider the circumstances required for a general change 

 of temperature, it will appear, from the facts and principles already 

 laid down, that whenever a greater extent of high land is collected 

 in the polar regions, the cold will augment; and the same result 

 will be produced when there shall be more sea between or near the 

 tropics; while on the contrary, so often as the above conditions are 

 reversed, the heat will be greater. If this be admitted, it will 

 follow as a corollary, that unless the superficial inequalities of the 



