456 
MR. DANIELL ON A NEW REGISTER-PYROMETER 
Table XVII. 
Linear Dilatations of Solids by Heat. 
Dimensions which a bar takes whose length at 62° is 1.000000. 
At 212° (150°). 
At 662° (600°). 
At Point of Fusion. 
Black-lead ware .... 
1.000244 
1.000703 
Wedgwood ware .... 
1.000735 
1.002995 
Platinum 
1.000735 
1.002995 
(1.009926 maximum, 
but not fused. ) 
Iron (wrought) 
1.000984 
1.004483 
(1.018378 to the fusing 
point of cast iron.) 
Iron feast) 
1.000893 
1.003943 
1.016389 
Gold 
1.001025 
1.004238 
Copper 
1.001430 
1.006347 
1.024376 
Silver 
1.001626 
1.006886 
1.020640 
Zinc 
1.002480 
1.008527 
1.012621 
Lead 
1.002323 
1.009072 
1.003798 
1.021841 
Tin 
1.001472 
1.001787 
Brass. Zinc £ 
1.007207 
Bronze. Tin 
1.001541 
1.007053 
1.016336 
Pewter. Tin 4- 
1.001696 
1.003776 
1.004830 
Type Metal 
1.001696 
The regularity of these several expansions is very striking. As long as the 
metal retains the solid form, the dilatation proceeds according to a fixed law, 
without any sudden starts or changes ; till assuming the form of a liquid it 
doubtless is subject to a different mode of action. 
I shall conclude these observations with the results of some experiments 
which I made to determine, if possible, the cause of the singular change of 
texture in platinum, when intensely heated in the black-lead registers, which I 
described in my former paper. Upon showing the bar so changed to those 
who were best acquainted with the working of this metal, they universally 
ascribed it to the action of sulphur : but nobody could explain to me why this 
action should require such a very intense heat ; as up to the temperature of 
melting cast iron, to which it had several times been exposed, no change took 
place ; but the bar remained perfectly soft and malleable. 
In De Ferussac’s Bulletin for November 1830, there is an abstract of my 
paper on the Pyrometer, which the Editor concludes with the observation, 
that “ unfortunately I inclosed in the crucible which contained the register 
