[ M ] 
large male Screw: To each of thefe male Screws is 
adapted a female Screw of Wood, clofed at one Ex- 
tremity with a Piece of Steel, excavated in the Cen- 
ter, to receive the fteel Pivots upon which the elec- 
trifying Glafs turns. Thefe female Screws of Wood 
are fo formed at their open Extremity, that they 
grafp and cover as much at the Poles, as nearly ren- 
ders what appears of the glafs Spheroid a perfed 
Sphere : this with a Defign, that the Wood may fix 
the more effedualiy, and embrace the eledrifying, 
Glafs. From the exterior Surface of one of thefe 
wooden female Screws, a circular Ledge rifes, and 
projects to the Height of about two Inches j the Am- 
bitus of which Ledge is excavated, to receive the Co;d 
that turns the eledrifying Glafs. This is what they 
ufe here inftead of our Tubes, and with furprifmg 
Effeds, fuch as greatly furpafs what you have yet fecn 
in England . The eledrifying Spheroid is turned by 
means of a Wheel about four Feet in Diameter, with 
the fame Motion, and exadly in the fame Manner, 
as the Spindle is turned round by the Spinning- 
Wheel: allowing a due Proportion to the Frame,, 
upon which the glafs Spheroid is mounted, that it 
may anfwcr to the Wheel that turns it. The Sides 
of this Frame, which ftand pcrpendicuhr to the Ho- 
rizon, are near as ftrong and as large every Way, as 
the Pofts of an ordinary Clofet-Door j and, f with the 
Ledges that join them at Top and Bottom, form a, 
redangular Parallelogram. The Front of this Frame 
is provided with filken Loops, conveniently difpofed 
in feveral Places, to bring to, and fix at a Contad with 
the eledrifying Glafs, Wires, Threads, Packthread, or 
whatever clfe is to be cled rifled. Into one Side of this- 
7 Frame* 
