[ 228 ] 
Fahrenheit will rife, when plunged in boiling water, 
in all flates of the barometer, from 27 to 31 inches 
Englifh. Among other ufes of this table, it will 
ferve for a direction to inftrument-makers, to make a 
true allowance, for the effedt of the variation of 
the barometer, if they are at any time obliged, to 
finifh a thermometer, when the barometer is above 
or below 30 inches ; but in general it fhould be their 
rule, to watch an opportunity of fixing the boiling 
point, when the barometer is adtually at the height 
prefcribed. 
I mull, upon this occafion, declare, how heartily 
I concur with M. de luc, in wifhing, that fonie 
common fcale, the fame in the number of its divi- 
sions, its point of o, and its boiling point, might 
be received, with unanimous confent, by phi- 
lofophers of all parts of the world ; that, for the 
Future, we might have one general language, for fo 
very general an objedt of enquiry and difcourfe, as 
the different degrees of heat arid cold. To mathe- 
maticians the comparifon of different fcales, is a 
talk of little labour. But among thofe who have 
a tafte for phyfical researches, and are capable of 
pur-fuing them, in certain branches at lea ft, with 
iome degree of advantage to fcience, as well as to 
themfelves, there are many, to whom every little 
calculation is a toil. Not having acquired the habits 
of it, in .the early part of their lives, they never can 
acquire them, in fuch a degree, as to be able to put 
a confidence in themfelves, and rely upon the accu- 
racy of their own conclufions. The eafe of fuch 
perfons Should, in- my opinion, be confulted. But 
thefe are not the only perfons interested. The in- 
conveniericies to be apprehended from a diverfity of 
Scales 
