128 History of Mechanical Inventions and Useful Processes . 
on the floor, with a large flat stone before him, and with a move- 
able flat stone-stand at his side. His fellow-workman stands 
beside him with a crucible filled with melted lead, and having 
poured a certain quantity upon the stone, the other lifts the 
moveable stone, and, dashing it on the fluid lead, presses it out 
into a flat and thin plate, which he instantly removes from the 
stone. A second quantity of lead is poured in a similar manner, 
and a similar plate formed, the process being carried on with 
singular rapidity. The rough edges of the plates are then cut 
off, and they are soldered together for use. 
Mr Waddell has applied this method with great success to 
the formation of thin plates of zinc for galvanic purposes ; and 
we have now before us some of those made in this manner. One 
of them is about the 75th part of an inch thick, and is not only 
smooth on its surface, but remarkably uniform in its thickness. 
8. Account of a New Stain for Wood , and a Yellow Dye for 
Cloth. By John Hill, Esq.* 
The new stain proposed by Mr Hill consists of a decoction 
of walnut or hickory bark, with a small quantity of alum dis- 
solved in it, in order to give permanency to the colour. Wood 
of a white colour receives from the application of this liquor a 
beautiful yellow tinge, which is not liable to fade. It is particu- 
larly adapted for furniture made of maple, particularly that kind 
of it which is called birds-eye, and which is commonly prepared 
by scorching its surface over a quick fire. The application of 
the walnut dye gives a lustre even to the darkest shades, while 
to the paler and fainter ones it adds a somewhat greenish hue, 
and to the whiter parts various tints of yellow. After applying 
this stain to cherry and apple wood, the wood should be slight- 
ly reddened with a tincture of some red dye whose colour is not 
liable to fade. A handsome dye is thus given to it, which does 
not hide the grain, and winch becomes still more beautiful as 
the wood grows darker by age. 
k4 Walnut bark, 1 ’ says Mr Hill, “ makes the most permanent 
yellow dye for dyeing cloth of any of the vegetable substances 
used in this country, for that purpose, with which I am acquaint- 
* Abridged from Silliman’s American Journal of Science, Vol. ii. p. 166. 
