140 REPORT—1846. 
The two systems of cross currents naturally divide themselves into four 
beds of opposite currents, namely, N.E. S.W., N.W. S.E.; with the first of 
each system, N.E. N.W., the barometer rises, and with the last of each, S.W. 
S.E., it falls, so that in the barometric wind-rose the maximum is found 
about the N.E., the prevailing system, and the minimum near the 8.W., the 
opposite current of this system. 
The extent of are which the wind-vane frequently describes, especially in 
stormy weather, also receives an explanation from these systems of cross 
currents. A contemporaneous S.W. with a N.W. wind will occasion large 
ares to be described between these points; the south-westerly gusts prevail- 
ing, directing the vane to that quarter; and the north-westerly immediately 
following, instantly occasions a change carrying the vane towards the N.W. 
These sudden and extensive changes are rendered more distinctly perceptible 
by means of a small kite flown with about 250 or 300 feet of string, or even 
more ; the distinctness and independence of the direction of the two currents 
are readily seen, as well as the difference in their strength. 
Col. Sabine has shown in his Report on the Meteorology of Toronto, that 
the intensity of the wind increases as the temperature increases. The con- 
sideration of these cross currents opens up to us another mode of contem- 
plating the force of the wind. It appears probable that the force diminishes 
on each side the line of greatest velocity. Now in order to obtain the true 
expression of this force, its numerical value, it will be important to correct 
the results, either anemometric or those obtained by estimation for the daily 
period ; this will give the value of the force of the currents then passing, and 
will in a great measure test the hypothesis. 
Section II. 
Discussion of Mr. Brown’s Observations. 
In the following discussion I have first arranged such of the observations 
collected by Mr. Brown, or deductions from them, as indicate the barometric 
pressure about the middle of each day at the stations before-named, as near 
as the data furnished by that gentleman will allow. These observations or 
deductions will be found in Table V. The arrangement is such that the eye 
may readily ascertain the barometric state of the atmosphere at any station 
on any day embraced by the area and period included in the table. The 
changes at any one station are also readily seen, the altitudes above 30 
inches being distinguished from those between 29 and 30, and those below 
29 also being distinguished from the rest. This table forms the basis of the 
following deductions which have been thus arrived at. The values corre- 
sponding to each day have been arranged with especial reference to the 
maximum and minimum of that day 7” space, that is, the station exhibiting 
the greatest pressure on any particular day has generally been placed first 
on the list for that day; and that exhibiting the least, last. At the head of 
each list are placed the directions of the crests as indicated by the observa- 
tions. Crests passing from N.W. to S.E. are distinguished by the odd 
numbers, and those passing from S.W. to N.E. by the even. When the 
observations give two slopes from a crest or trough passing between such 
slopes, the observations have been arranged to exhibit this. After the 
arrangement of the observations, the lines of the greatest diminution of 
pressure corresponding in a majority of cases to tranverse sections of the © 
waves, aud exhibiting either their anterior or posterior slopes, are inserted. — 
These are succeeded by the direction of the wind on each side of the crests 
as given in Mr. Brown’s plates, and the discussion of each day’s observation 
is concluded by a few explanatory notes. 
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