144 Scientific Intelligence. 
The mean diurnal variation for summer, is pel? ners 
autumn, . ° 6 219 
winter, . : 4! 36/3 
oe ee 
“ “ spring, 9. s 8 10"7 
The se dip for 1840-1, was ‘ : ous TAR QO 
1841-2, 71° 180 
The mets journal nnbiniien four iaieam from July, 1838, 
to June, 1 
The maximum of the —— for two ora was 30°810 
Minimum 29-074 
ange, : ’ 1-736 
The maximum temperature was fr BE 3 : 103°°0 
Minimum ‘ ‘ ‘ . —4°'5 
Range for four years, : 107°°5 
Mean temperature of Washington seven tout years, 53°°97. 
— following is the result of four years observations of the —_ 
o. of —— from the South, 32-7 
Southwest, , 56°2 
nS . est, 38°4 
“ » Northwest, 70°3 
7 = - North, . ‘ 26°3 
- # Northeast, 43.2 
" # East, ; j 18:9 
Southeast, é 20:3 
Calm, j s 52:8 
~ Mean direction of the wind, N. 71° 51’ W. 
Mean annual amount of rain, 41°21 inches. 
The subject of meteorology is every year attracting increased atten+ 
tion both in this country and in Europe, and the perseverance of its cul- 
tivators has been rewarded with considerable success. We have ad- 
vanced so far that we can see very clearly what is wanted to ensure 
further progress. A vast number of meteorological journals are kept 
in the United States, and a great amount of industry expended upom 
them. We need however more uniformity of system—in many cases 
better instruments, and in some quarters a great increase of observerse 
In order to be able to investigate satisfactorily the phenomena of a great 
___ storm, we need observations throughout its entire extent, from stations 
not more than fifty miles from each other,—observations with good in- 
struments and upon a uniform plan. Is this idea too gigantic to be re 
ined Let us see what materials we have to depend upon. 
The general government has manifested a very commendable zeal 
Observations of the thermometer have long been made 
military posts, but recently their number has been much 
