196 PROCEEDINGS OF THE CANADIAN INSTITUTE. 
of Lake Huron on the 46th parallel, descending in the Western 
States nearly to latitude 41°. The winter mean of 25° has in On- 
tario an average latitude of 43°, while in the Mississippi valley it 
reaches as far south as North-Western Missouri in latitude 39°. 
When the occasional extremes of winter cold are considered, the in- 
fluence of the Great Lakes is found to be even more marked than 
in regard to average temperature. The lowest temperature in the 
past twelve years in Toronto, (lat. 43° 39’) was only —18°-4, Fahr. : 
Hamilton, (lat. 43°.16’) records —20°.5, and Windsor, (lat. 42° 19’) 
~19°.5,—while portions of the Niagara and Lake Huron districts show 
no temperatures lower than 12° below zero. Within shorter periods, 
not exceeding in any one instance eight years, the following tempera- 
tures were recorded at meteorological stations in the Mississippi and 
Missouri valleys :— 
@airos ME: Flato7S Oi eee eed aici chet te ee —16° 
Sty liouisw Mois latiS8° iSipmeme. oes ie ciete cleee ee —— ies 
West Leavenworth, Kansas, 39° 20’.............. —29.0 
Indianapolis’ lid) SOS Airmen ere apace as —25.0 
Watayettes (ALK x. ..7 seen ete reer, ei). 
To instance minimum temperatures in the past eight or nine years 
at stations further up the Mississippi valley is superfluous. Tem- 
peratures 40° below zero have been recorded at places in this valley 
no further north than the Canadian stations cited. During the pre- 
sent winter temperatures as low as—32° have been recorded in the 
State of Missouri. The lowest in Toronto has barely exceeded —13°. 
In the winter of 1874-5, the coldest on record in Ontario, when in 
Toronto the minimum temperature was—16°, temperatures as low as 
—39° were reported in Northern Illinois. 
Tn short, the lake region of Ontario has as mild a winter mean as 
the Mississippi valley two hundred and fifty miles farther south, and 
eastward of the Rocky Mountains it is only to the south and east of 
a line drawn from Lake Erie to North-Western Texas that the ther- 
mometer does not occasionally fall as low as the lowest ever reached 
in the milder parts of the Province of Ontario. 
It is interesting to notice in connection with the influence of the 
Great Lakes in modifying the cold of winter that the shore of Lake 
Michigan, opposite Chicago, has a mean winter temperature nearly 
four degrees higher than that of the city mentioned, and that while 
the pear grows with difficulty at Chicago, the much more tender 
