1833.] Expansion of Metals. 14h 
Specific gravity Increase Elongation by annealment, is 
of in parts of | indecimal parts of 
hard. annealed.} volume. an inch. 10 feet unit. 
Pure gold, 19,313 | 19,136 00925 301973 ,000164 
Silver 
a ae t 10,404 
To compare the relative expansions, the increase of bulk, or volume, must 
be divided by three, to reduce it into linear elongation, when, as before 
stated, the transverse will be found much to exceed the longitudinal ex- 
10,239 01611 08244 | 3000687 
pansion. 
Having explained the Sects and results of this digression, and ima- 
gining the bars replaced as before, we will proceed to the remainder of 
the experiments with the steaming apparatus : 
Tenth Series. 
Thermometer, Readings of the micrometer. 
sy hess in bar in Gold Silver Copper 
aY- | south. | north.| steam.} Iron. | (add 2525)|(add 4065)| (add 2297) 
eo Phe La SOO Wee Ales 
Dec. 3.) 78,5! 78,3 — 937 —449 +865 —965 
Ween 79,2 | 79,2 
212,1 | 211,8 | 211,5 | +1279 —383 +224 —240 
to 212,0 | 212,0 ices —381 +222 
212,0 | 212,0 1264 
5 P.M-1917,9 | 211,7 | | | 
Ascending temperature, dif- C0) oO ts) oO | 
ferent for each metal, ...... 133,6 133,4 133.1 132,83 
Dilatation (adding nits be- 
DPEEIIIOIS) co, oc ce csi seses. 2207 2592 3423 3022 r 
Eleventh Series. 
ial toes gs twa —9ll| —445 +865 | —977 |, 
sa 212,3 | 212,0} full | +1278 —377 +227 —203 
to | 212,2/212 | steam] +1266 —401 +220 —202 
es | 212,1 | 212,1 | (steam} -++-1204 —404 +175 —226 
. 211,9 ' 211,9 © less) | +-1202 
o oO o 0 
Range of temper. ascending,..| 133,7 133,7 133,7 133,5 
Ditto for last readings,......; 133,6 133,6 133,6 133,5 
Dilatation, first readings,....] 2183 2593 3423 3071 
Second ditto, ........0..... 2114 2566 3375 | 3048 
Tn this last series the steam was allowed to run down on purpose to 
try the effect: and it will be seen that it was sensibly felt by all the 
metal bars, even while the mercurial thermometer scarcely indicated the 
fall; for as before remarked, the bars were far more sensible thermo- 
meters than the small mercurial instruments. 
The expansion however by the last experiment has been purposely cal- 
culated, to shew the maximum influence of such a cause. 
