96 E. Loomis—Observations of the U. S. Signal Service. 
0°05 inch. The observations make the pressure at Dodge City 
0°08 inch less than at Denver, while the chart makes the former 
0.025 inch greater than the latter. A part of these discrepan- 
cies may be ascribed to the fact that the observations at the 
different stations were not all made on the same years. Ac- 
cording to the Dakota Southern Railroad Survey the elevation 
of Yankton is 1,202 feet. If we adopt this value, both the Jan- 
uary and July observations at Yankton accord pretty well with 
the observations at neighboring stations. The observations at 
Chicago seem to indicate a small zero error in the barometer. 
The pressure at Salt Lake City reduced to sea level appears 
to be 0-472 inch greater in winter than in summer; while in 
Central Asia the difference between winter and summer amounts 
to an entire inch. It is evident that the same cause operates in 
North America as in Asia, but with diminished energy. 
Comparison of barometric minima in Hurope and America. 
The monthly Review of the weather for 1877 published by 
Dr. Neumayer of Hamburg, contains a summary of the results 
derived from the observations of 1876 and 1877. I propose to 
Pee gi some of these results with those obtained in the United 
tates 
Rate of progress of barometric minima.—Dr. Neumayer has 
given for each month of the years 1876 and 1877 the average — 
daily progress of barometric minima in Europe expressed in 
myriameters. I have reduced these values to English miles 
oh hour, and the results are shown in column 4th of the fol- 
owing table. For the purpose of comparison, I have placed 
in column 2nd the velocities deduced from three years observa- 
tions in the United States as published in this Journal, vol. x, 
pel ave also reduced to a tabular form the velocities given 
in the monthly Reports of the Signal Service since Nov. 1875, 
T.oomis.!Sigc. Ser Europe 1 Loomis (sie Ser. Europe 
January | 267 | 33-3 | 16-8 (July 249 | 27-6 | 14° 
February 32-70 | 28°5 | 14-0 ||August 184 | 22:8 | 145 
March 30°5 | 30°2 | 18-2 ||September | 22°9 | 21°5 | 15-0 
pril 97°5 24°] 14°9 ||October 25°8 21°4 197° 
May 23°5 | 23°6 | 12-7 ||November | 29°0 | 25°5 | 15°8 
June 21°6 | 23°6 | 14°5 ||\December | 29-3 34:0 | 15°8 
| Year 26-0 | 26°3 | 15°5 
and have determined the averages for each month. These 
results are shown in column 3d of the table. They are derived 
from forty-four months of observation, and refer to the region 
between the Atlantic Ocean and the meridian of 100° from 
Greenwich. 
