os) Mg 
180 Bibliography. 
course of prevailing wind to be from several degrees south of west. 
To come to any trustworthy results on this great point, the observations 
must be very accurate, and the direction of the wind, not on the surface, 
but in the main body of the clouds, must be observed. From local 
causes or other forces, the lower current often varies greatly, from 
the prevalent direction. Probably much more attention must be giv- 
en to this particular than the regents have yet required. The pre- 
vailing wind, that is, the resultant of all the winds, may then be found 
at the south of the S. W. direction, and in the course of the great moun- 
tain chains from the Gulf of Mexico. The report also contains a great 
amount of observations on halos, storms, frost, time of flowering of 
plants, aurora borealis, coming of birds, time of harvesting wheat, rye, &e. 
and of ripening of various fruits, appearing of reptiles, insects, &c., 
which make a rich treat to the connoisseur in these subjects. 
It closes with a catalogue of plants in the vicinity of Penn Yan, Yates 
County, which does no little credit to Dr. H. P. Sartwell, an accurate 
and ardent botanist. 
‘In concluding the present annual report, the regents recur with 
pleasure to the evidently flourishing condition of the colleges and 
academies subject to their visitation.” So let it be in time to come. 
7. Report of Experiments on Gunpowder, made at Washington 
Arsenal, in 1848 and 1844. By Capt. Atrrep Morpgcai of the Ord- 
nance Department. Washington, 1845. 8vo, pp. 328. 4 plates. 
—This Report embodies the results of many thousands of accurate ex- 
periments made by Capt. Mordecai, under government authority, with 
instruments constructed in such a manner as to insure perfect accuracy. 
Having had the satisfaction of inspecting the instruments, and of hearing 
from Capt. Mordecai an account of the methods of experimenting, we 
can speak of them with the greater certainty. ‘The force of gun- 
powder, since the time of Hutton and the French experimenters, has 
been calculated by means of the balistic pendulum and of a gun pen- 
dulum. The gun (in these experiments a twenty-four and a thirty-two 
pounder) is suspended in an iron frame, hung on knife edges of hard- 
ened steel, like a balance beam, the whole supported (a load of 10,500 
Ibs.) on massive stone pillars. The recoil is measured on a limb of 
brass, having a curve, of which the frame work and the gun are the 
radius, and graduated to read to seconds by means of a vernier which 
is moved by the recoil, and retained at the point of greatest vibration 
by a slight spring. When the gun is adjusted and at rest, its axis is a 
horizontal line, and the vernier stands at zero on the scale. | 
Ata distance of only fifty-five feet, (between the centres,) is inserted 
the pendulum block for receiving the shot and measuring its velocity. 
