94 Canadian Record of Science. 
temperature in summer of the North Saskatchewan and 
Peace River valleys is substantially the same as that of 
Montreal and Quebec. Similarly, the isothermal lines that 
pass through the thickly settled districts near the southern 
boundary of the plains are those of northern Ohio and 
Illinois. In fact, it is a truth proved by long observation, 
that the summer climate, in relation to agriculture, is 
warmer all over.the western plains than it is in central 
Ontario. Spring opens earlier, too. Plowing is very often 
begun, all the long way from Red River to the Rockies, by 
the last week in March; and in Manitoba, which is the 
coldest corner, spring is never postponed beyond April 5. 
In the fall, on the other hand, plowing may generally be 
continued until the first of December, and sometimes much 
later. The Lethbridge News, of February 16th, this year, 
(Lethbridge is near Fort McLeod, 100 miles south of Cal- 
gary), says: ‘‘ Winter is generally believed to be practically 
at an end. The thermometer registered 57° at noon.” 
Karly in April, then, the sun dissipates the light snow, the 
dry air evaporates it, leaving the ground dry, and plowing 
and seeding go on simultaneously. In a few days the seed 
germinates, owing to the hot sunshine. The roots receive 
an abundance of moisture from the thawing soil, and pene- 
trate to an astonishing depth into the loosened loam. By 
the time the rains and heat of June have come, abundance 
of roots have formed and the crop rushes to quick maturity. 
The enormous Crops are owing just as much to the opening 
power of the frost as to the fertility of the soil; this is a 
peculiarly favorable effect of the swift change from sharp 
cold to intense heat which characterizes the climate of that 
region. The summer weather is often extremely hot—fre- 
quently reaching 100 degrees; but this is a scorching, nota 
sweltering heat. It is the direct burning of the sun’s rays 
—not a heat resident in the air: hence you mark an in- 
stantaneous and grateful relief when you step into the 
shade, or catch the breeze. Sunstrokes and loss of vigor 
through heat, which so often accompany summer days here 
when the mercury may not goso very high, are almost un- 
