1805.] 
img the hearth with raw ftone, &c. and by 
introducing the blaf& in the common way, 
the defired end is produced. 
, . EE 
MR. ROBERT CAMERON’S (ROSAMOND- 
STREET, CLERKENWELL), for Im- 
provements in Sawing-Machines, and 
Jor a new Methed of working Sawing- 
Machines. ; 
This invention confits in a method 
of ftretching’a humber of faws placed near 
ene another, and in a method of hold- 
ing the wood while fawed. The whole 
pian is defcribed and iliuftrated by draw. 
ings in the fpecification, to which we 
mult refer the reader for ore ample de- 
tails. We may, however, obferve, that 
the patentee applies hs method to the 
fawing of thin boards in general ; and he 
oblerves, ** I have detcribed them [the 
examples] as methods which I practife ; 
although, in vanier-fawing, a number of 
faws, placed near one another, may be 
firetched by a wedge, or other mechanical 
inftrument, going through a number of 
faws. And in order that it may ftretch 
them all equally, it will be neceflary to be 
at great pains to adjuft all the faws to 
their proper lengths, which may be done 
by ftretching all the faws feparately by 
the fame weight, and by means of a 
guage adjufting them to their lengths.— 
Or vaniers may te {awed by a fingle faw, 
and a contrivance in the carriage to regu- 
Jate the wood fidewife, and a contrivance 
in the faw-frame to regulate the faw fide- 
wife, fo as to perform as many operations 
on the fame piece as may be found necef- 
fary ; which last contrivance may be ufed 
with one or any convenient number of 
faws. Very narrow vaniers may likewife 
be fawed by means of circular faws, 
which are fixed on an axis, and move 
without it in one direction.” 
The new method of working the faw- 
ing-machines confilts in applying the 
power of the fteam-engine, either by di- 
rect application of the powers of the en- 
gine, or by raifing water to turn a wheel, 
which works the fawing-engine ; and the 
improvements in the machines confift in 
adapting thefe machines to the fawing of 
mahogany and other hard woods ufed for 
vaniers, and to the fawing of thin boards 
ip general. The methods made ufe of to 
faw mahogany and other hard woods into 
vaniers, confift in fixing the wood to be 
cut on a moveable carriage, and in fixing 
a faw, or a number of faws, in a frame, 
“which being moved to-and fro, faws the 
wood, which, on the moving carriage, is 
brought forward to be cut. : 
New Patents lately enrolled. 
145 
MR. JOHN SWIFT SAXELBY'S (DERBY), 
jor a Method of making White Lead dif- 
ferent from the Methods now pra&ifed. 
Inftead of applying heat by means of 
horfe-litter, or tanner’s-bark, Mr. Swift 
makes ufe of the fenfible heat which is 
produced and communicated by the com- 
buftion of fuel, and this he keeps to fuch 
a height as produces the oxydation in an 
effectual manner, without caufing the acid 
in the pots to be volatilized to a greater 
degree than is neceffary for the imtended 
purpefe. This is done by making the 
fire in 4 proper ftove or receptacle, with 
its apertures, &c. fo that the operator 
fhalf have it in his power to manage and 
regulate the fire and the communication 
of heat in the ufual manner. The ftove 
is fo built as to be able to receive the pots 
containing the ufual charge of metallic 
jead and acid, and to admit of the fame 
being regularly placed and difpofed, and 
fhut up, but that none of the fmoke, va. 
pours, or other immediate exhalations, 
from the fuel, fhould be admitted within 
the faid room cr fpace. The heat of the 
place is regulated by thermometers 5 and 
for the purpale of preventing any. waiteful 
or pernicious excefs of heat, a valve is 
made in the room that will fuffer the ef. 
cape of the heated air when neceffary.— 
The ftepper of the valve is fo conttructed 
and fixed to the thermometer, &c. as to 
Open of its own accord when the heat of 
the room.is too great, while a diminution 
ot temperature fuffers it to clofe. The 
patentee has found by experience, that the 
belt ftate of temperature is from 90? to 
100% Fahrenheit, during ten or twelve 
days, and from 100° to 110° the next 
eight days; and that the heat be recu- 
larly and equaily ncreafed about ten de- 
grees for each fucceffive portion of eight 
days, until the expiration of about fix 
weeks, or until the vinegar or other acid 
fhail have evaporated, when the white 
lead is to be feparared and ground for 
fale. 
In fome cafes, water or fteam is made 
ufe of as the medium of communication 
through or by which the heat is tranfmit- 
ted inta the room ; and in thefe cafes the 
water or iieam may be uleful’y employed 
for general purpefes that conftitute no 
part of the invention, though economy 
may thereby be promoted. 
n- =e a 
MR. EDWARD GREAVES’'S (SHEFFIELD), 
for Improvements on Razors. 
Thefe improvemenis relate chiefly to 
the manner in which the handle is falten- 
ed to the blade by means of fprings and 
catches. 
