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Jachfon executed it for me in the Year 1736. as is 
repreiented in Fig. 2 and 3. Tab, II. 
The 'Description of the Inflrtment. 
Fig. 2. AB a round Rod of Steel or Brafs a Quar- 
ter of an Inch thick, and 3 Feet 1 Inch long : 
When the Rod is of Brafs 3 Feet long, the Point 
A mu ft be of Steel 1 Inch long, to prevent its 
wearing away, or lofing its Point $ which conical 
Point is made to ferew on and off. 
I had the firft Rods made x~ Inch thick at 5 , and 
of the fame Thicknefs 6 Inches upj but I found 
Inconveniences from that Form, and that a Rod all 
of a Size was better. 
CD, cdy are two iron Supporters, joined by a 
flat crofs Bar at Bottom Dd two Inches long, in the 
middle of which is a Point \ Inch high under B , which 
goes into an Hole at the Bottom of the Rod B , and 
ferves to keep the Rod in its Place at Bottom, as the 
crofs Bar** having an Hole in it, thro' f which the 
Rod paffes, does in the middle or about -| up the 
Supporters, and the Point A goes into a fmall Hole 
in the under Side of the Lever 5 all which keep the 
upright Rod firm and Ready in its Place. The iron 
Supporters are flat, or parallel to the Front , of the 
Machine from C to X and c to x, where they are 
twifted half-round, fo that the lower Parts XD 7 
xd ftand at right Angles with the upper Parts. This 
Contrivance gives the freer Accefs to the Rod for the 
Sand or Fluid into which the Machine is fet to 
mcafure the Heat of it, the Supporters (landing 2 
Inches afunder at Dd$ and that the Degrees of Heat 
2 may 
