‘83 a Report of the Committee 
making a correction, we recommend, that the boiling 
point fhould be adjufted when the barometer is at 29.8, 
if the perfon clinics to do it in fleam; or when the baro- 
meter is at 29Y, if he choofes to do it in clofe vcffels, 
with the ball immerfed to a fmall depth under the water. 
Our reafon for pitching upon this precife height is, that 
thereby the boiling point will differ from Mr. de luc’s 
boiling point, by a Ample fraction of the degrees of his 
common fcale, namely three-quarters of a degree higher. 
We are informed by Mr. de luc, that the method he 
ufed in adj ufting the boiling point, though he forgot to 
mention it in the Recherches fur les Modifications de V At ~ 
mofphere , was to wrap rags round the tube of the ther- 
mometer, and to try it with the ball immerfed in water 
in an open veffel, of the form deferibed in the above- 
mentioned book, while boiling water was poured at dif- 
ferent times on the rags, in order that the quickfilver in 
the tube might be heated, if poflible, to the fame degree 
as that in the ball. As well as we can judge from the 
abovementioned experiments in open veflels, and from 
the few trials we have made of this method, we are in- 
clined to think, that the boiling point adj ufted this way 
Will in general differ but little from that adj ufted in fleam 
at the fame height of the barometer, efpecially if the 
frrermometer be not very long, and do not extend a great 
way 
