Sailing and Steam- Vessels. 265 



such as have in a similar way been successfully done in 

 domestic and public buildings. (See observations by me on 

 this subject, Arch. Mag., July 1837.) 



I do not wish, however, to be understood as inferring that 

 even any such mode of spontaneous ventilation as could be in- 

 corporated with the framework of ships, would prove at all 

 times sufficient for the ventilation of an overcrowded vessel. 

 The immense deterioration of atmospheric air, by 600 to 800 

 persons crowded into a small space, where the cubical contents 

 bear no proportion to the cubic feet of air required for each 

 person (10 cubic feet being considered as requisite per minute 

 to afford a wholesome atmosphere), renders such arrangement 

 next to hopeless without mechanical agency. So long as ves- 

 sels are overcrowded, hardly any plan can be devised which can 

 afford an adequate supply of fresh air to lower-decks during 

 night ; all that can be done, without artificial means, is to 

 prevent positive injury to health, by affording a constant and 

 uniform supply of fresh air below decks at all times, which 

 surely is deserving of the most serious consideration. 



In very crowded ships, such as troop-ships and others, 

 whether any arrangements, such as alluded to, are provided or 

 not, the wind-fan, as improved, could be advantageously made 

 use of. Two or more of these machines, worked by hand, 

 would speedily renovate the air of a lower deck, by means of 

 flexible pipes communicating with different parts of the vessel ; 

 in emigrant ships, the passengers would, doubtless, very gladly 

 work these machines for the sake of fresh air in warm lati- 

 tudes. 



Another ventilator could likewise be advantageously applied 

 in many cases in sailing ships, namely, an exhausting pump, with 

 a hose or pipe, on the principle of pumping out the foul air, 

 or a condensing or force-pump to throw in atmospheric air, 

 worked like the pump of a ship or fire-engine. One of tho 

 earliest recommendations of a pump for ventilating purposes 

 noticed, is by Dr Desagulier. He mentions in his Experi- 

 mental Phil, that, in the year 1727, he brought before the 

 Royal Society an attempt to shew how damps or foul air 

 may be drawn out of every sort of mine by an engine which he 

 contrived. ** The engine consists of a triple crank with three 



VOL. XXXVI. NO. LXXII. APRIL 1844. S 



