ON THE THERMAL PROPERTIES OF ALCOHOL. 
133 
on the horizontal lines which represent change of volume without increase of pressure, 
where vapour in contact with liquid is being condensed. 
14. The temperatures given are those read directly, with two exceptions, viz., 
242-8° was altered to 242-6°, and 243-25° was altered to 243-55°. The reason for this 
alteration was that in drawing the isobaric curves, deduced from the isothermals, the 
observed points at those temperatures differed from the curve in every case by the 
same amount. This error is really a very small one at such high temperatures, and 
may depend on some mistake in reading the pressure under which the bromonaph- 
thalene used as a jacket was boiling. 
It is to be remarked that by this double method of smoothing any great irregularity 
of temperature would at once be detected; this is shown by the corrections above 
referred to. 
