10 E. Loomis—Results from an examination of the 
n inspection of this map will show that the centrifugal 
force arising from the circulation of the wind around the storm 
center cannot be the principal cause for the fall of the barom- 
eter, for otherwise the form of the isobars would be more 
nearly circular. 
With regard to the direction of the major axis of the isobars, 
there is but little tendency to uniformity ; nevertheless, the 
most prevalent direction is about N. 35° E., which is almost 
identical with the result derived re the observations of 1872 
and ’73. 
Great and — changes ow temperature. 
to the great and sudden anges ‘of ‘temperature st 
r f 
will now present some additional facts bearing upon the same 
question. In the Report of the Chief Signal “Officer for 1878 
is given the maximum and minimum epee of each da 
in 1873 at 40 stations in the United States and Canada. 
have examined these tables to find all the sages in which the 
difference between the maximum and minim of the same 
day amounted to at least 40°. The Slicetae “table shows all 
the stations at which so great a difference was observed, and 
also the number of cases which occurred each month, 
Diurnal Change of Temperature of 40° and upwards in 1873. 
ws Blail. 3} e eyed? 
Lat.| Lon. | 3/5) 3| 5) $i 8 |S) Pi Bis 18] 318 
seg SS eZ 258 E18 
Denver__..__- so a4lsBa 0 a} 5| of 2} al of al al af #| | aban 
Fort Sully ....|44 39100 40) 3)-.| 2) 4}-.| 1}--| 1] 5} 9}--| 1126 
Cheyenne... _. 41 y tees 1} 1/--| 1/..] 41 3|_-| 2] 3 3] 220 
Virginia City __|45 2}..| *| #| *| 2] 1) #| *| 1] 2] 3iz1 
Deeckanaldge “las Yel oe 8 Hea ES Bas 
Fort Garry --- 2, 96 5 ee ees WE 7 8 
San Antonio ..|29 25} 98 25)__|__|__ 2 8 
La Crosse__... 43 48) 91 27) 3) 2] 1 Boats 
Halifar 2.02. 44 40| 63 35|__| Li__[.-| Ti.t--t 1 1 # OM OF 4 
Geneva .....- 53) a Tia Hd Gerd ee 
sabes cabs 16, jo} Aje-) Uefa} pL} 8} 4) 8) 8 
ee. 41 52| 87 38|__| 1-_|..[ 1 2 
Leavenworth _'39 19 i a 1 
ae 53 a 1 
Morgantown ..|39 40 79 55/ *|__| 1 *| *) #1 
| Oswego ...... 28) 76 35) 1 ing e! 
An asterisk shows that observations for the month indicated 
are wantin. 
The number of stations at which a difference of 40° between 
the maximum and minimum of the same day was observed in 
7 
