622 KANSAS CITY REVIEW OF SCIENCE. 
that it is not required of me to make an extended reference to them, although 
technical terras in every science deserve to be frequently analyzed that their spe- 
cial application may be borne in mind. In meteorology " an area of low barome- 
ter " is merely the space over stations where, in any extended survey of the pres- 
sure of the atmosphere, the barometer shows the least height. Stations of like baro- 
metric reading being connected a series of rings is usually formed about the space 
of least pressure and this space as it moves over the country produces an imag- 
inary line (generally imaginary, though in some cases, as a cyclonic disturbance, 
the/ track is apparent enough) which line is usually in a direction from the south- 
west to the northeast (to the Gulf of St. Lawrence) or easterly from Manitoba 
(with a southerly bend over the lakes) to the same point. 
The following diagram, though rude, may serve to illustrate the tracks of 
low barometer during July, 1883. This month is chosen because of some curious 
" twists " made over that portion of the country included in Colorado, Nebraska 
and Kansas, which can only be explained by considering the position of antago- 
nistic areas of high barometers at this time : 
w 
From Manitoba to the Gulf of St. Lawrence there were four tracks, nearly 
similar. The curve marked " A " represents them, as a whole. 
From Colorado four others were charted. Three of these (marked " C ") 
passed off the coast near the same point as those from Manitoba. One (marked 
B) took a southeasterly direction, after going nearly directly north, to Yankton, 
and left the coast at Norfolk, Va. This turned northeasterly over the ocean, 
however. The dates were as follows : 
From Manitoba: No. i on the ist and 2d; average velocity 39 miles per 
hour. No. 4, on the 9th and loth, average velocity 42 miles. No. 5, on the 
nth, 12th and 13th; average velocity 24 miles. No. 6, on the 13th and 14th; 
average velocity 28 miles. 
From Colorado: No. 2, on the 2d, average velocity 41 miles; this moved 
first northeast, then took a backward twist southwest and then went northeast 
again. No. 3, from the 4th to the 7th; average velocity 30 miles. At first the 
motion was slow and due east — rate 100 miles a day. Then it raced northeast 
at nearly a thousand miles per day pace. No. 7, from the 15th to the 17th; 
average velocity 28 miles. (This is marked C.) No. 8, on the 20th to the 24th; 
average velocity 18 miles (marked B). 
Nearly every one of these latter was deflected and delayed at that portion of 
