bailing and Steam- Vessels. 171 



not muster more than two quarter masters, and six fore- 

 mast men capable of working," attracted the attention of the 

 Royal Society of London ; and, as remarked by Mr Watson, 

 p. 172, Phil. Trans. 1742, " of these two very ingenious and 

 industrious members, the Rev. Dr Stephen Hales and the Rev. 

 Dr Desaguliers, the first of whom introduced an instrument 

 which he called the ship's lungs, and the latter a machine, 

 which was an improvement of the Hessian Bellows." 



In the year 1735, Dr Desaguliers first brought forward an 

 account of an instrument or machine for changing the air of a 

 room, by forcing in fresh air or removing foul. (Phil. Trans, 

 vol. xxxxix. 437.) This machine, which he named " Centrifu- 

 gal bellows," he recommended for extracting the foul air from 

 between the decks in ships, and supplying fresh air. It was 

 very similar to the wind-fan used at this day. He considered 

 it an improvement on, and more effectual than, Mr Papin'*s 

 bellows, as being able either to suck out the foul air, or throw 

 in fresh. It was evidently a revival of the plan of a ventila- 

 tor communicated to the Royal Society of London by Denys 

 Papin in 1705, who says, in a letter to Dr Fred. Slare — " I 

 don't question you have seen the new contrivance, an account 

 of which was printed at Leipsic, in Actis Eruditorum, anno 

 1699, with this title, * Rotatilis suctor et pressor Hassiaeus,' 

 and it may be applied for wind as well as water." " I have, 

 therefore, improved the Hessian bellows," &;c. (vol. xxiv. Phil. 

 Trans.) The improvement of M. Papin consisted in making 

 the vanes of the fan eccentric in place of concentric, or he 

 changed its cylindrical into a spiral form, which adaptation 

 has of late years been so highly recommended. By working it 

 with his foot, he could produce a wind to raise a weight of 

 two pounds — (Ree's Eno.) Dr Desaguliers did not, however, 

 adopt M. Papin' s plan of the eccentric vanes, and though he 

 otherwise improved the machine, it was never very effective. 

 Dr Ure remarks, in the Arch. Mag. 1837, *' from the defec- 

 tiveness of its construction, as well as the small area of its 

 discharge-pipe, it was probably not misnamed a philosophical 

 toy by Sir Joseph Ackworth, then first Lord of the Admiralty, 

 who went down to Woolwich to see its performance in ventila- 

 ting the hold of H.M.S. Kinsale." It is but fair, however, to 



