958. AN ACCOUNT OF THE 
The brass registers are therefore distant by the mean of these tri- 
als, POKOHHHOHAHHDHOHHHHACHHHHOHHHDHHHHFHTFFODAFHH FOG e000 000 1200-069 inches. 
Deduct* error of chain,, 013 
1200°056 
As compared with the chain reduced to 55, andstretched by a weight of 
19 lbs. avoirdupois. 
When 19 Ibs. additional were put on, the distance of the registers-was as. 
follows: 
Mean of 4 Thermometers. Reduction to 55, Distance of registers exceeding chain, Excess above 100 feet. 
SSI SU: 125 165. 040 
Se8 arg - °125 162 037 
58-0 092. 000 022 
Mean, "033 
Deduct, O13 
Distance of the registers, 1200°020 
The distance therefore i is 1300° 020 inches, as measured by the chain: 
reduced to the same temperature of 55, and stretched 2 a weight of 38 Ibs, 
the difference is ‘027 inch, or 002 feet, on 100 = 
sao e 
41. THE rods were now substituted for the chain between the registers. 
By ine brass wires were stretched across at right angles, at the register marks 
* Occastonep by the irregularities of the table om which it was stretched. This equation was 
calculated, 
