182 Suggestions for Ventilation of Sailing and Steam-Vessels. 



As the plan of ventilating-tubes by Mr Sutton has been so 

 long known and tried at different periods, it would appear with 

 considerable success, it is well deserving of consideration whe- 

 ther this plan could not be so far improved as to render it a safe 

 and useful mode of ventilation for sailing vessels — not overcrowd' 

 edvi'iih passengers ; for in the latter case, no plan of this kind 

 can be adequate from the obvious difficulty of having tubes of 

 sufficient size and number to produce a constant renovation 

 of the air. But in ordinary circumstances, by enlarging, as 

 much as conveniency will admit, the foul-air tubes from the 

 respective ceilings or beams of the under-decks, cabins, bread- 

 room, hold, and well, leading to the galley or cooking-fire ; and, 

 secondly, by providing ample fresh-air tubes to convey air down 

 to the lower part of these places, a very beneficial system of 

 ventilation could be maintained. But the difficulty, as regards 

 communicating these tubes, with the galley-fire and danger 

 from sparks, must, as a preliminary point, be got the better 

 of, which, in my opinion, might be done, by making the hori- 

 zontal foul-air trunk, which collects the air in one body from 

 the different ramified tubes, pass through a cylindrical boiler 

 of small diameter heated with steam or hot-water raised by 

 the galley-fire, but entirely separated from it, at least the ex- 

 tracting pipe to have no connexion with the galley-fire, but 

 simply passing through the steam or hot-water, and the foul- 

 air escaping at a sufficient elevation. As the air, when rarified 

 in the tube, will immediately receive motion, it is of no conse- 

 quence as regards the principle of establishing a current, whe- 

 ther the air is heated by coming in contact with the fire itself 

 in the ash-pit, or not. There will indeed be the difference of 

 temperature between steam-heat and that of the ordinary 

 fire, to diminish to this extent the velocity of the current ; 

 but this may be so far compensated by the enlargement of 

 the air-extracting pipe in passing through the boiler, and by 

 the uniformity of heat ; besides which, what is most import- 

 ant, all danger from tubes communicating with the ash-pit 

 and galley chimney will be entirely avoided. The same fuel 

 which would create a draught by Mr Sutton's plan, would 

 raise steam or hot-water. As salt-water would be probably 

 used in the boiler, the evaporation might be made subservient 

 to other purposes. 



(To be concluded in next Number.) 



