TRANSACTIONS OF THE SECTIONS. 195- 
90'5 gallons of water at starting. 8 gallons of water at stopping. 
232°67 revolutions per minute for 103 hours. 
Increased during last half-hour to 274°67 revolutions. 
Highest temperature . . . . . . 209° 
Lowest temperature . . .. . . 168° 
41° 
General Result of First Series with 50 gallons or 500 lbs. water agitated at 88°64 
revolutions per minute. 
. 
, 
' No. of Duration of Degree, including 
_ Experiments. Experiments. radiation. Degree per hour. 
a): ° 
1, Increase in 9 hours 21 2° or 2°35 per hour. 
: 2. 2? 9 ” 37 0 2? 4°10 27 
3. re Chee acer nie & 4°37 ‘s 
. 4. Paty, gg eld Nagas 3°05 rs 
1 5. Py iets 58 28 ” 4°48 ” 
q 6. aM Fag 42 11 ae 4°21 a 
1 6/22°56 
General average increase per hour ..,..... is 37°6 Fahr, 
Loss by leakage 10 per cent. 
General Result of Second Series with 10 gallons or 100 lbs. of water agitated at 
: 236°67 revolutions per minute. 
No. of Duration of 
Experiments. Experiments. Degree, increase. Degree per hour. 
Naw Increase in 5 hours 58°45 or 11°69 per hour. 
2. ” 1 1 a? 75 22 6°8 1 2? 
3. a? 11 a) 62 2? 5°39 2? 
4, ” 11 ” 41 ” 3°72 ” 
4/27°61 
Loss by leakage, &c. 10 per cent. 6°90 
MECHANICAL EQuivALENTS. 
First Series,—These were obtained by means of Prony’s Friction Break applied 
to a correctly turned pulley of cast iron, fitted in the upper part of the vertical 
‘wooden spindle of the agitator. The friction bracket was carefully equilibriated on 
the pulley by means of weights, oil, and tallow until it made the same number of . 
_ reyolutions as before ; the box having previously been emptied of its water. 
The following were the results :— 
Ist, That 500 Ibs, of water agitated at the rate of 88°64 revolutions per minute 
were heated 3°-38 per hour by an expenditure of 29°000 lbs. per minute. This is 
equivalent to 1690 lbs. raised one degree. 
Then 29:000 x ok 
_ Second Series.—That 100 lbs. of water agitated at the rate of 232°67 revolutions 
“per minute were heated 6°27 per hour by an expenditure of 1°8 H. P., or 59°400 x 
60=356°400 lbs. This is equivalent to 621 lbs. raised 1° in one hour. 
_ From the preceding result it appears that the mechanical equivalent varies as the 
quantity of water used in the experiment, and the rate of agitation; the larger 
quantity of water agitated by 88°64 revolutions giving an equivalent of 1030 lbs., 
‘and the smaller quantity giving only 621 lbs. when agitated 232°67 revolutions. 
=1030, equivalent to 1 Ib, being heated 1° in one hour, 
9 Mechanical Structure of the ‘ Great Eastern’ Steam Ship, 
te By Joun Scorr Russert, F.R.S, 
_ he author laid before the Section some of the mechanical details of the eonstruc- 
tion of the great ship now building at his establishment at Millwall. The first point 
ated to the peculiarity of her great size; the second, on which her merits or 
emerits as a piece of naval architecture depended, was the general aT or lines: 
] 
