204 
Mr Brookedon’s qf Wire-Drawing. 
pressing-board bh. This patent was enrolled in June 1821. — 
Soe London Journal of Arts^ \o\. i\. 1 ^. 
5. Mr Brookedon's Improvement on the Method of Drawimg 
> Cylindrical Wire. 
The improvement which we propose at present to notice, was 
made by Mr William Brookedon of Poland Street, and was se- 
cured by patent on the 20th September 1821. The usual me- 
thod of making cylindrical wires, is to draw them through holes 
made in plates of steel, iron, or other metal. In this method, 
the holes were liable to be galled or enlarged by the wire in 
passing through them, so that the wires were less equal and 
cylindrical than might have been desired. The method which 
Mr Brookedon proposes to substitute in place of the old one, is 
founded on the ingenious idea of drawing the wire through cylin- 
drical or conical holes drilled in ‘‘ Diamonds, Sapphires, Rubies, 
Chrysolites, or any other Jit and proper hard gems or stones!"^ 
Although the wire may be drawn through either end of the 
hole, yet the inventor prefers entering the wire at the smaller 
end^ and drawing from' the larger end of the holes. 
It is very remarkable, that Mr Brookedon has not enume- 
rated among his gems the Garnet, which we consider as better 
fitted for the purpose than any which lie has mentioned. It is 
not only the cheapest and most easily obtained of them all, but 
has the property of giving less friction than almost any other 
substance. This interesting property of the garnet was esta- 
blished by the curious experiments of Coulomb on pivots 
6. Account of Mr Witty^'s Improvement m Pumps. 
The usual method of working pumps, either in distilleries, &c. 
or on board ships, is to force the water to the top of the barrel, 
and allow it to run off to a lower level. 
It is quite clear, that if the water in this case descends from 
‘ the top of the pump to a place of delivery much below the top 
of the pump-barrel, the fall of the water through this height is 
a mechanical force which is entirely wasted, and which may be ac- 
tually employed in raising the water through a part of the pump- 
* See the new Edition of Ferguson’s Lectures, Edin. 192?, vol. ii. p. I7I, 172. 
