1889-90.] TWENTIETH MEETING. 31 



could repeat thousands of lines of Gaelic poetry, which he had no doubt 

 were handed down from one generation to another. 



Mr. J. J. Mackenzie, B.A., read a paper entitled " A Preliminary List 

 of Algae collected in the neighborhood of Toronto." 



TWENTY-FIRST MEETING. 



Twenty-first Meeting, 5th April, 1890, the President in the chair. 

 Donations and Exchanges since last meeting, 35. 



Mr. R. F. Stupart read a paper on " Meteorological conditions during 

 the past winter." 



He said that the intense heating up of land and sea near the equator 

 causes an up draught of air, which, ascending to the upper regions of the 

 atmosphere, then flows away towards higher latitudes. Just north of the 

 tropics a large portion of this upper current descends again to the surface 

 and forms a belt of high pressure outward, from which, on the southern 

 side, the north-east trade wind blows towards the equator, while on the 

 northern side there is a general drift of the atmosphere from the south- 

 west over the middle latitudes. The position of this belt of high pressure 

 alters as the sun changes in declination, and hence the mean limit of the 

 drift varies with the season, and varies also according as it is over land or 

 ocean. Having this general flow of atmosphere from the south-west over 

 the middle latitudes there must be return currents, and a large proportion 

 of these are found in anti-cyclones moving south-east. In winter the 

 formation of anti-cyclones occurs over the continents where the air cooled 

 by radiation becomes heavy and contracts, and in consequence, air in the 

 upper regions over the comparatively warm oceans flows towards the con- 

 tinents. It is probably not wrong to surmise that the almost permanent 

 high pressure over Asia draws its supplies from over the Atlantic, and 

 that the Pacific supplies America. The mean limits of the south-west 

 drift at the surface of the earth may practically be identified with the 

 mean track of a vast and persistent system of areas of low pressure or 

 cyclones, which can be traced nearly around the globe, and which varies 

 more or less from season to season and in different years. 



During December an unusually persistent and rapidly moving stream 

 o areas of depression from the Pacific passing over the northern part of 

 the lake region kept back the flow of cold continental air which in average 

 seasons at intervals flows over Ontario and Quebec in the form of anti- 



