16 EK. Loomis— Contributions to Meteorology. 
barometer; column 4th was obtained in a similar manner and 
shows the reduction from Pike’s Peak to Denver when the 
barometer on Pike’s Peak stands at 17-6 inches, and column 5th 
shows the correction due to a change of 0-1 inch in the 
barometer, which correction is negative when the pressure 
increases. 
Reduction of barometric observations. 
Mt. Washington Pike’s Peak Sum 
and sea- eee. and Denver. and Sitnatenti: 
Therm. Barometer 23°5 inches, Barometer 17°6 inches. Barometer 23°3 inches, 
Reduction. Ahad hari aia Reduction. tba ks ages Reduction. Bg ng ong 
—10° 7-158 “0021 77600 0070 
at 7054 0056 7541 0060 
0 6°943 “0061 7448 0022 
+ 5 6°831 “0039 7367 0022 
10 6°732 “0015 7°290 0013 
15 6-657 0032 [227 0023 
20 6°586 0032 7179 0108 
6 6°520 0047 7112 0077 6:98 — ‘0180 
30 6°450 0068 7-055 0086 6°942 0138 
35 6374 74 6°993 0113 6°888 0182 
40 6°307 “0035 6°929 0132 6°833 —°0216 
45 6-239 0024 6°858 0150 6-791 0286 
50 6-173 0024 6786 0157 6°742 —°'0343 
55 6107 0027 6°725 0160 6°663 —*0307 
60 6°037 0026 6716 0057 6599 —°0285 
65 5°968 0022 6°558 —*0267 
70 6520 —*0370 
75 6480 
80 6°432 
The irregularities of these numbers may be alone 
takine the mean of each three consecutive numbers in 
; g 
é formule of reduction to sea-level hitherto employed 
are admitted to be unsatisfactory for great elevations, it does not 
e toc apse that they are correct for small elevations. 
seem 
For elevations less than 1000 feet the error of reduction is less 
palpable than for an ralewaaion of 6000 feet, but it is probable 
that the error is only proportionally diminished. 
Height cf the Signal Service stations. 
In my 12th paper I gave the results of some computations 
sca tnd ted considerable errors in the assumed heig 
e of the stations of the Signal Service. The publication 
