1822.] 
steam-engine and mechanism may not be 
impeded or subject to derangement whilst 
travelling. 
This is one of the most essential im- 
provements in locomotive machines, 
and promises all the advantages that 
may be expected from its present ap- 
plication. The steam-engine, and 
those parts of the mechanism of which 
the exposition to shocks might endan- 
ger the progress of the carriage, are 
suspended by means of four chain 
slings, with helical springs within them, 
whose motion is such as to ensure 
security. 
5thly. The revolving perch. 
To prevent the horizontal position of 
the carriage from being deranged, 
Mr. Griffith employs, as has been 
already mentioned, a revolving perch, 
peculiarly adapted to the bed or frame 
of the front wheels, and whose move- 
ment amply ensures the safety re- 
quired. 
In addition to every other kind of 
security that the most profound reflec- 
tion has enabled Mr. Griffith to adopt, 
there are two safety-valves calculated 
at fifty pounds upon a square inch, 
whilst every part of the steam appara- 
tus has been proved at the rate of 200 
pounds upon asquare inch. 
From these safety-valves, as well as 
from the cylinders, the steam is con- 
ducted into two condensers, formed of 
flat copper tubes; that part of the 
steam which is condensed, falling to 
the bottom of the condenser, is con- 
veyed to the reservoir of water for fur- 
ther use, whilst the uncondensed 
Proceedings of Public Societies. 
145 
steam is conducted through the chim- 
ney, and here extinguishes such sparks 
as may occasionally find their way 
from the charcoal, combined with 
coke, of which the fire is made. 
The fire, placed under the boiler, is 
surrounded by iron plates, and so far 
removed from the part of the carriage 
destined for goods, that no possible 
danger can be apprehended. 
Vhe weight of the carriage (which 
is in form of a caravan,) and the whole 
apparatus, may be calculated at 14 
ton: itis destined to carry three tons 
of merchandize, making a total of four 
tons and a half, upon wheels conform- 
able to the regulations established by 
law, and subject to the usual re- 
strictions. : 
We understand that, actuated sin- 
cerely by a disposition to promote the 
public welfare, it is Mr. Griftith’s inten- 
tion toreduce the pricesnow paid for the 
carriage of goods throughout the coun- 
try ; not that he can flatter himself with 
the hope of being speedily usefulon many 
roads, since the construction of a num- 
ber of waggous demands not only ex- 
tent of funds, but also considerable 
time. Should it be proved, however, 
that Mr. Griffith’s steam-carriages can 
convey goods in an equally secure man- 
ner with other waggons, at the rate of 
five miles per hour, or 100 miles per 
day of twenty travelling hours; and, 
at a freight, twenty-five per cent. 
cheaper than the present prices, there 
can be no question that he will have de- 
served well of his country and of 
mankind. 
PROCEEDINGS OF PUBLIC SOCIETIES. 
—>—— 
ROYAL INSTITUTION. 
R. Rocet, in his eighth lecture 
ou Comparative Physiology, took 
a comprchensive view of the subject 
of Respmation. The necessity of this 
function, he remarked, would scarcely 
have been anticipated, from our pre- 
vious notions of the wants of an ani- 
mal, founded on the known properties 
of organized matter; and yet observa- 
tion shows, that the continuance of life 
is more immediately dependent on 
respiration, than even on the circula- 
tion itself. Insects, for example, that 
jive without any vascular circulation 
of their juices, require the {roe intro- 
duction of air into every part of their 
bodies, ‘The necessity for air appears, 
also, to be more urgent than for food ; 
Montuty Maa. No. 372. 
since animals may subsist a considera- 
ble time without nourishment, but all 
will speedily perish if deprived of air. 
The results of Spallanzani’s numerous 
experiments were stated in ilustration 
of this principle. 
Aquatic animals being precluded 
from the benefit of the direct action of 
the air in its gaseous state, or as it 
exists in the atmosphere, receive its 
influence through the medium of the 
surrounding water, by which it is ab- 
sorbed in large quantities, and applied 
to the organs of respiration, In the 
lower Zoophytes, this influence ap- 
pears to be exerted by the intervention 
of the surface of the body; so that in 
the polypus, for example, while the 
interior surface digests the food, and 
U performs 
