DAG AN ACCOUNT OF THE 
‘Indeed if we suppose this to have been the case, this determination will be 
. found to agree with the others as well as can be expected. 
Date. Thermometer. Fa Sota Equation pan eaieh | educa Comp. | Reduced 
tanec jf beam.\ oF steps. |S01 inch.| to 69. mean. \to 1217. 
Before. | After. | Mean. inch | 
1819, Jan. 23) 60 58 59 +037 1601 | | 16-047 | 7 1238 16°062] 
| A5 +211 |+:035 15°78 | 16:026| 1366 “180 
25} 54°5 »} 62 58°3 | +093 |-L-O14} +026 }16:00. | 16133] 2155 090) 
66 —049 16:083) 16°034] 1287 083 
26 Al5 | +-254 [+003 | -++--040 | 15:929| t6:226] 1382 °340) 
25°7 24:8 |+4-437 14-037 |-1-028 | 15-643] 16-164] 1157 | -129 
: 34:2 as 346 |-+b: 028 +-:028 | 15°800| 16°146} 1099 0623, 
Mean, rejecting that of the 26th, 1217 16099 
a ae 
23°9 
27 
| 24) 43 A7 
Tue cxtremo difference of the 6 is -068 division or 017 inch, on 301 
inches. 
28.. THE operations by which the lengths of the other three rods were 
determined, cannot be made so clear as the preceding for want of divisions 
on the ivory scale, which at this stage of the business had only been attach- 
edtothe vod 1.2. ‘The detail will therefore be rather more summary, the rod 
marked 2.3.was measured twice, the steps being made on the ivory studs. 
‘The length of the rod as defined at one end by the brass edge, at the other 
by an arc drawn on ivory was, 
Inches, Comp. 
300-9601 1173 
9413 , 1168 
Mean, 300-9507 1170 
| 29. Tus two rods were now compared with each. ether Being: tied 
firmly with pieces of wood of the same thickness between them, they were 
