( ' 6 9 ) 
whofe upper Part is open. It is evident from the Make 
of this Inftrument, that if it be inclin’d in carrying, no 
Prejudice will be done to the Liquor, which will always 
be right, both in the Ball and the Tube, when the In-' 
ldrument is fet upright. If by Heat, the Air at C be fo 
expanded, as to drive the Liquor to the Top of the 
Tube, the Cavity A will receive the Liquor, which 
will come down again and fettle atD, or near it, accord- 
ing to the Level of the Place where the Inftrument is, 
as foon as the Air at C returns to the fame T:noi in 
refpect to Heat and Cold. To preferve the name Le- 
gree of Heat, when the different Obfervatims are made, 
the Machine is ik’d in a Tin Vdfcl F E, fill’d with 
Water up to g h, above the Ball • and a very fenfible 
Thermometer has alfo its Ball under Water, that one 
may obferve the Liquor at D in each Experiment, 
when the Thermometer ftands at the fame Height as 
before. The Water is pour’d out, when the Inftrument 
is carried, which one may do conveniently by means 
of the wooden Frame of Fig. IV. which is fet upright, 
by means of three Screws, fuch as s , and a Line and 
Plummet / P. The back Part of the wooden Frame' is 
reprefented by Fig. VI. where, from the Piece at Top K, 
hangs the Plummet P, over a Brafs Point at N : M m 
are Brackets to make the upright Board K N continue 
at Right Angles with the horizontal One at N. The 
Vilth Figure does likewife reprefentthe wooden Frame 
and Screws. The Vth Figure reprefents the Machine 
feen in Front, fuppofing the Forepart ofthe TinVeffel 
tranfparent. And here the Brafs Socket of the recurve 
Tube, into which the Ball is fcrew’d, has two Wings 
at 11. fix’d to the Bottom, that the Ball may not break 
the Tube by its Endeavour to emerge, when the Wa- 
ter is pour’d in as high as g h. 
i B 2 After 
i 
