174 REPORT—1863. 
development of heat acted injuriously in three ways: firstly, its absorption in the 
hot chamber diminished the working pressure; next, its development in the cold 
chamber increased the resistance ; and, thirdly, in interfering with the action of the 
respirator. He also stated that the mechanical necessity existing for keeping all 
arts of the machine at once in motion, producing excessive cushioning, resulted 
in a loss of effect, represented by from two to four cubic feet of air for every foot 
of air contained in the working cylinder at the best point of its stroke; and he said 
that the operation of these causes necessitated the employment of excessive heat 
or very slow speed—an almost fatal alternative. The second type of air-engine, he 
said, required the employment of extremely large apparatus, because there was a 
pressure-diagram and a resistance-diagram caused by the working of a pump, and 
the total diagram must always, therefore, amount to three times the effective dia- 
gram. In the air-compressing apparatus he described, he pointed out how these 
defects were obviated :—That there was no necessary transference of heat from the 
hot to the cold chambers, but that the total heat absorbed in the hot chamber 
was converted into mechanical effect, and therefore a lower degree of heat might 
be employed. That there was no difficulty in the arrangement from cushioning in 
the working cylinder. That the highest point of pressure obtained in the gene- 
rator was not again lost, as it was in all other cases; and that, in addition to the 
improvements effected on the first type of engine he described, the new apparatus 
was capable of receiving the whole effect obtainable by the use of the second form ot 
apparatus without its resistance, and at high instead of low pressures, He finally 
teed to the advantages to be derived from the use of air instead of steam, 
which he stated to be a saving of fuel, freedom from risk of explosion, burstin 
under air-pressure being comparatively harmless, if it should occur; but he state: 
that no safety-valves were required in the apparatus described by him, as it was 
self-coverning in the production of pressure. It was not liable to derangement. 
It would work reversed as well as forward. Insurance was not affected by the use 
of the engine; and the compressed air might be applied in any situation, being 
laid on like gas, to be used when and how it was required. 
On Extinguishing Fires. By C. B. Kine. 
The subject, he remarked at the outset, was one of grave importance, touching, 
as it does, the safety of our lives and our aye In large manufacturing 
towns and cities, where immense wealth, in the shape of merchandise, is closely 
acked and stored, the importance of an improved construction of fire-proof ware- 
houses cannot be overrated. It was the object of this paper to give in a succinct 
form a few facts collected from practical experience. After referring to the im- 
portance of carefulness, and remarking that though buildings could not be made 
wholly fire-proof, they could be constructed with a view of rendering them im- 
ervious to fire, viz. to resist, not to assist, any fire that may break out upon their 
oors, the author described certain fire-proof buildings, and noticed the mode of 
applying water to extinguish fires. The best means of arresting fires, he observed, 
was a very wide question, as the only limit to the means was the expense. On 
the Continent, generally, the whole was managed by Government, and the firemen 
were placed under martial law, the inhabitants being compelled to work the en- 
gines. In extinguishing fires of any magnitude, the steam fire-engine must ever 
hold the foremost place, not only on account of the development of power, but on 
the more important score of economy. Having alluded to the first steam fire- 
engine constructed in England by Mr. John Braithwaite, in the year 1830, and the 
taking up of the subject by the Americans subsequently, he described the main 
features of the engines constructed by different companies, and stated that Messrs. 
Merryweather, and Son were now manufacturing steam fire-engines, and had suc- 
ceeded in bringing out two very good serviceable engines, named the ‘Deluge’ and the 
‘Torrent.’ He next gave a description of steam fire-engines used for service in the 
water, and ecnisledted by expressing a hope that the discussion of the subject might 
bring to light features which had been hidden from the public generally, and 
increase to greater efficiency the present arrangements for the suppression of fires 
in many of our large towns and cities. 
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