Mr Brunelie^s Patent Pocket Copying-Pi'ess. S9S 
tion lakes place, and the comparative colour of the flame, with 
the varied phenomena of the exotic lambent flame, \lili aflbrd an 
elegant measure of that explosive force which has been disarmed 
before its transmission from the portal below. 
This lamp has been submitted to the ordeal of explosive at- 
mospheres, with the most complete success. No explosion what- 
ever occurs within the cylinder. When the explosive aimo- 
spliere, mixed with the product of combustion, passes towards 
the lamp, the colour of its flame is changed, and it shoots up in- 
to the bell or funnel, (which carries off these chemical products of 
flame, in order that they may be mixed with the explosive atmo- 
sphere, before it passes into the cylinder), and as the explosiv^e 
mixture increases, a lambent attenuated flame plays silently round 
that of the lamp, which Anally disappears ; and when it has 
reached its maximum^ it is tranquilly extinguished. , 
4. Account of a Nexv Patent Pocket Copying-Press^ hyJA. J. 
Beunelle. 
This ins:enious and useful invention is shewn in section in 
Plate X. Fig. B., where a is the bottom of the press, made 
of the best gun-metal, and hh a pressing-board of wood, hal- 
ving above it a steel-plate spring cc, which rests upon ledges, 
and supports the pressing-board by the screw d. A strong steel- 
lever moving on the plane presses near its centre ^n the 
head of the screw d ; and g is another lever, moving oil the 
joint to which the power of the hand is applied. The damp- 
ing apparatus contained in the box consists of a metallic cy- 
linder, having several sheets of fine linen rolled round it, of the 
sAitie size as the vsheets of paper employed. 
In using this press, the original letter is put into a transfer- 
ring-book, and a blank-leaf of paper turned over Upon it. A 
sheet of the damp lineri is then laid upon the blank-leaf, and 
above that a leaf of oiled paper. The bOok being shutj and in- 
troduced between da and 55, the hand is applied td the levei* 
which presses do\vn the lever e with great power, and commu- 
nicates the pressure to the book hk means of the ktidb d df the 
VOL. VI. XO. 12. APEIL 1822. u 
