IMPORTANT SUBSTITUTE FQR STEAM. 
109 
FOREIGN VARIETIES. 
PROOF OP FRENCH SILK.— The 
French have adopted a system of security 
against fraud in the sale of silks, by submitting 
it to exam ination and expeiiment in an esta- 
blishment called the conditio??. Silk exposed 
to a hiunid atmosphere, and yet more to wet, 
will imbibe a considerable quantity of humi- 
dity witliout undergoing any perceptible 
change in external appearance. The esta- 
blishment, of which there is one at Lyons and 
another at St. Etienne, receives about three- 
fourths of the whole consumption of silk. It 
is submitted during twenty-four hours to a 
temperature of from 18 to 20 degrees of 
Reaumur (72.1- to 77 of Fahrenheit), and if the 
diminished weight be from 2g to 3 per cent, 
tire application of the high temperature is con- 
tinued during another twenty-four hours. On 
a certificate granted by the condition as to its 
true weight, the invoice is made out. The 
means of correctly ascertaining the real humi- 
dity of vsilk are now the subject of investi 
gation at Lyons, and it is believed that the 
purity of the material will, ere long, be as ac- 
curately tested as is that of metals by an assay. 
The quality of silk is estimated by deniers, 
which represent the weight of 400 ells 
would off of on a cylinder; the number, of 
course, increases with the fineness. The Alais 
silk is sometimes reeled from three to four 
cocoons, and weighs only from eight to ten 
deniers ; sometimes from seven to eight co- 
coons which will give eighteen to twenty de- 
niers. Of French organzines, the quality va- 
ries principally from twenty to thirty-six de- 
niers, and of French trams from twenty-six 
to sixty deniers. — Dr. Bowring’s Report. 
THE SUBMARINE VESSEL.— The ex- 
periment with this machine took place at St. 
Ouen, as proposed. The vessel was re- 
peatedly sunk to the depth of ten or twelve 
feet, and re-appeared on the surface at differ- 
ent points. M. Godde de Liancunrt got into 
it, and remained there a quarter of an hour. 
He stated that he did not experience the least 
inconvenience, or any difficulty of respiration, 
daring his voyage under water. An oftioial 
report upon the subject is about to be submit- 
ted to the French Government. 
USEFUL ARTS. 
IMPROVEMENTS IN THE STEAM- 
ENGINE. — Mr. Price of the Durham glass- 
works, has published a plate of a steam srfety- 
valve and chest, which has been in constant 
use for upwards of seven years, without acci - 
dent. The following is a brief description of 
his apparatu.s, which, if we mistake not we 
had the pleasure of noticing when it was first 
used Instead of the common valve, there is 
placed on the top of the steam chest a cup, 
with an apperture for the steam to escape. In 
this cup a loose brass hall (weighed to tlie 
pressure the boiler can bear) is placed. 
When the steam rises about that pressure, the 
ball also rises, and allows the steam to escape 
through the waste. There is an elhow-pipe 
connected w'ith the steem-chest below the 
ball seat, which also enters the waste-pipe. 
In this is a handled valve, by which the engi- 
neer can blow off liis steain, or regulate it. 
Let it be perfectly understood the ball 
cannot be weighed by the engineer ; so soon 
as the steam rises above the safety-pressure, 
it escapes, and when sufficiently blown off, 
the ball returns to its seat. 
SUBSTITUTE FOR STEAM.— The fol- 
lowing plan has been addressed by Mr. John 
Galt to the editor of the Greenock Adverti- 
ser .-—Take a cylinder and subjoin to the bot- 
tom of it, in communication, a pipe ; fill the 
pipe and the cylinder with water ; in the cylin- 
der place a piston as in that of the steam-en- 
gine, and then with a Bramah’s press, and a 
simple obvious contrivance which the process 
will suggest, force the water up the pipe, the 
pressure of which will raise the piston. This 
is the demonstration of the first motion. Se- 
cond. When the piston is raise(|, open a cock 
to discharge the water, and tiie piston will 
descend. This is the demonstration of the 
second motion, and is as cosnplete as the mo- 
tion of the piston in the cylinder of the steam- 
engine, and a power is attained as effectual as 
steam, without risk of explosion, without the 
cost of fuel, capable of being applied to any 
purpose in which steam is used, and to an 
immeasurable extent. The preservation of 
the water may, in some cases, be useful, 
and this may be done by a simple contrivance, 
viz. by making fhe cock discharge into a con- 
ductor, by which the water »nay be conveyed 
back at every stroke of the piston into the 
pipe, at the end of which the Bramah’s press 
acts. 
ELECTRIC LIGHT.-Mr. Lindsay, a 
teacher in Dundee, tdrmerly lecturer to the 
Watt Institution, succeeded, on the evening 
of Saturday, the 25th ult., in obtaining a con- 
stant electric light. It is upwards of two 
years since he turned his attention to this 
subject, blit much of that time has been de- 
voted to other avocations. The light, in beau- 
ty, surpasses ail others; lias no smell, emits 
no smoke, is capable of explosion, and not re- 
quiring air for combustion, can be kept in 
sealed glass jars. It ignites without the aid 
of a taper, and seems peculiarly calculated for 
fias houses, spinning-mills, and other places 
containing combustible mateiials. It can be sent 
to any convenient distance, and the apparatu.s 
for producing it may be contained in a common 
chest, — New Monthly Magazine, Oct, 1835, 
QUICK AND CHEAP MODE OF RAIL- 
WAY lliANSlT WnilOUT LOCO- 
MOliVE-ENGlNES. 
Mr. Editor, — A great deal has been said 
on both sides for and against the undulating 
railway principle, but hitherto no satisfactory 
practical results have been obtained on which 
to found a definitive judgment respecting it ; 
and although the shareliolders of the Liver- 
pool and Manchester Railway are deriving 
c nsiclerahle profits, owing to the immense 
traffic betw'een tbe two tow ns, still there are 
doubts if many other roads will pay at all, 
the expense of locomotive-engines being so 
