152 
in the pumps. Mr. Barton told us the quantity of water raised 
by each stroke was about 64 gallons. He reckoned the power Of 
pressure on the piston equal to 81b. per inch square. Two boilers 
14 ft. 6 inches and 14 ft. 4 inches in diameter. Depth of water in 
these boilers about 3 feet. About five tons of coal consumed every 
15 hours, or one day’s work. 
64 x 64x '7854-3217 square inches the piston 
8 
lbs. 25736 power to work the engine. 
But the water raised at each stroke is only 512 lbs. average, for 
31 x 31 x 7 "75 = 7 447*7 5 + 7447 '75 = 14895'5 inches or 64 gallons. 
On the motion of Mr. Binney, seconded by Mr. Dickin- 
son, it was resolved unanimously — That the thanks of the 
Society be given to Mr. Green for his interesting and valu- 
able donation. 
“Description of a New Anemometer, 1 ” by Mr. Peter 
Hart. 
On the appearance of Mr. Fletcher’s admirable paper “ On 
the Speed of Air in Flues,” it appeared to me that an anemo- 
meter more easily read and less costly than his was desirable. 
With this view I devised the present one, which may be 
broadly described as a common U tube gauge laid in a 
sloping position so as to form the hypotenuse of a right- 
angled triangle, the perpendicular of which is the true 
reading. 
The following description will explain its construction : — 
It consists first of a base board furnished with levels and 
levelling screws ; to this is hinged the board carrying the 
U tube, which may be called the sloping base ; on this sloping 
base is secured the U tube furnished with a scale and ver- 
nier capable of being read to the rwotli inch. By means 
of a screw passing through the sloping base, and resting on 
the lower base board, the former can be made to assume 
any angle with the latter, the angle being determined by a 
quadrant fixed to the lower base board. 
