59t> JWr. cavallo’s, ^hermometrical 
intermediate degree between the blackened thermome- 
ter and the naked or unpainted one. If the colours 
had not the proper degree of denfity, the effects were 
very different: thus a thermometer painted with a light 
blue was lower than another thermometer painted red 
with good carmine. 
I fhall now defcribe the manner of conftrudting the 
fcales of thofe thermometers, which was contrived fo as 
to be very expeditious ; becaufe fome of thofe thermome- 
ters were often broken by fome accident or other, and 
that new fchemes often required new thermometers, to 
conftrudt the fcales of which in a formal manner would 
have required a very long time. Thofe methods there- 
fore may be of ufe to other perfons. 
When the thermometers were intended to be expofed 
to the flame of the lamp, at a given diitance from it, their 
fcales were drawn upon flips of paper which were glued 
to their tubes in the manner reprefented by fig. i. The 
thermometers were then fet horizontally upon a book, fo 
that their balls were out of the book, and at any required 
diftances from the flame of the lamp, which diftances 
were meafured with a pair of compafles. But when the 
thermometers were only to be expofed to the Sun, I then 
ufed the following very expeditious method, fee fig. 2. 
Upon an oblong board abcd of about 14 inches by 18, 
4 and 
