Sailing and Steam- Vessels. 269 



ture to the air, is highly deserving of general application, and 

 ought never to be overlooked in ventilating arrangements. 



The importance of keeping the furnace-room cool is of 

 great consequence, especially in warm climates, as the heat 

 is injurious to the health, — the cold air rushing to the furnace, 

 falls like lead on the heads of the stokers. To remedy the 

 over-heating, though it cannot prevent the draught, a plan, 

 proposed by Mr Holdsworth of Dartmouth, has recently been 

 tried in the Victoria and Albert, Royal Steam Packet, of hav- 

 ing the bulkheads of two plates of sheet iron, and a stream of 

 cold water kept constantly flowing between. 



Another plan of ventilating, suitable for steam-ships, 

 which the small space it occupies recommends, is the very in- 

 genious method adopted by Mr Oldham at the Bank of Eng- 

 land, of forcing in fresh air, by an air-condensing pump, 

 through the interstices of iron cases heated by steam, the 

 power being taken from the steam-engine, as described in the 

 Civil Engineer's Journal, March 1839. This plan gives both 

 fresh air and a modification of its temperature. 



Mr Taylor's plan, described in the Transactions of the So- 

 ciety of Arts, London, 1810, of pumping out impure air from 

 mines by an air-exhausting cylinder, likewise admits of ap- 

 plication to steam-vessels. Mr Taylor's engine discharged 

 more than 200 gallons of air per minute.* The idea of a mo- 

 tive power to work ventilators is of very old standing. A 

 plan is given in the Phil. Trans. 1758, of using the fire-en- 

 gines at mines for this purpose. t Various other suggestions 

 might be made to apply ventilation to steam-ships — even the 

 suction from the motion of the paddle-wheels might be made 

 subservient to this purpose ; but it is superfluous to say more 

 on what admits of so many ways of attainment. 



It is unquestionable, that the same share of attention has 



* Mr Taylor's plan consisted in attaching a pump of simple construction to a 

 small fall of water of about 12 feet. Steam-power could be substituted for water. 



t It was first proposed by Erasmus King, to have ventilators worked by the 

 fire engines of mines; and Mr Fitzgerald, in 1758 (see Phil. Trans.), sug- 

 gested an improved method of doing so. I have alluded to the similarity of 

 mine- ventilation with that of ships ; thus, by having a series of flexible pipes con- 

 nected with a wind-engine, or an air-pump attached to the 8team-«ngine, im- 

 mense supplies of air might be driven in, or drawn out, where required. 



