164 ROYAL SOCIETY OF CANADA 



available data referring to that ancient lake, and gives a comprehensive 

 discussion of the various facts bearing on the whole subject. On page 243 

 of this work, the fluctuations of the Great Salt Lake, which are known 

 with tolerable certainty since 1840, and have been accurately determined 

 in late years, are represented in a diagram, which affords a basis of com- 

 parison for the more isolated facts noted in British Columbia. This dia- 

 gram shows that the Great Salt Lake stood low and was affected by no 

 very strongly marked variations in level, from 1840 (and probably much 

 earlier) to about 1865, when a steady and continued rise began. This 

 culminated in 1870. but the great height of the water was maintained 

 to about 1877 with slight variation. It then began to decline, and 

 in 1890 was not fïir above its appi'oximate mean level for the period be- 

 tween 1840 and 1865. The diagram thus shows a change of precisely the 

 same kind with that which would explain the phenomena met with in 

 southern British Columbia, but, so far as can be ascertained, the maxi- 

 mum epoch of humidity was reached in British Columbia nearly ten years 

 later than in Utah. It thus seems possible that the climatic change 

 mav have been of a progressive character, and that its effect was first 

 rendered apparent in the more southern latitudes. It may be conjectured 

 that a progressive change of this kind might result from modifications 

 in position or size of the ruling anticyclonic areas of this part of the 

 northern hemisphere. Thus the decrease in importance, or movement to 

 the southward, of the permanent anticyclonic area of the adjacent North 

 Pacific, would permit a greater rainfall and more humid conditions gen- 

 erally in the southern part of British Columbia, tending to assimilate 

 these to those now characteristic of the northern part of the province. 



Clai-ence King, writing in 1878, after referring to what had then been 

 ascertained respecting the oscillations of Great Salt Lake, quotes other 

 facts from the area of the 40th Parallel Survey, which led him to believe 

 that a period of increased moisture and greater snowfall had been entered 

 on in late yeai"S. He refers to the occurrence of avalanches in the Sierra 

 Nevada which had "begun to pour down into the true forest belt and to 

 sweep before their rush con.siderable areas of mature tree growth," adding 

 " it is obvious that no such avalanches could possibly have occurred 

 during the germination and growth of this forest." He also makes the 

 following further statement which ap])ears to favour a similar belief : — 

 •• On the summit of the Central Pacific Pass are a considerable number 

 of well grown coniferous trees. An examination of them during the 

 construction of the Pacific Railroad [about 1867] showed that they were at 

 that lime being seriously damaged, and in some cases actually killed, by 

 the drifting snow-crystals borne on the strong west winds during the 

 Avinter storms, the notch or depression of the pass making a sort of funnel, 

 throuf'-h which the wind blew with unusual violence, concenti-ating its 

 freight of sharp snow-crystals, which not only wore away some of the 



