[ *5 ] 
To prevent the above-mentioned Inconveniencies, 
and preferve the Healths and Lives of that valuable 
Part of the Nation, the Seafaring People, many 
Schemes have been thought of; particularly the 
Machines of thofe two very worthy ingenious and 
induftrious Members of this Society, the Rev, Dr. 
Hales , and the Rev. Dr. Defaguliers ; the firft by an 
Inftrument which he calls the Ship's Lungs *, and the 
latter by a Machine f, which is an Improvement of 
the HeJJian Bellows : But as thefe have been laid 
before the Society by the Gentlemen themfelves, 
1 (hall pafs them over, and proceed to mention the 
Contrivance commonly made ufe of, I mean the 
Wind-fails. They are made of the common Sail- 
cloth, and are ufually between 25 and 30 Foot long, 
according to the Size of the Ship, and are of the 
Form of a Cone ending obtufely : When they arc 
made ufe of, they are hoifted by Ropes to about 
Two thirds or more of their Height, with their 
Bafis diftended circularly by Hoops, and their Apex 
hanging downwards in the Hatch- ways of the Ship; 
above each of thefe, one of the common Sails is fo 
difpofed, that the greateft Part of the Air, rufhing 
againft it, is dire&ed into the Wind-fail, and con- 
veyed, as through a Funnel, into the upper Parts of 
the Body of the Ship. Thefe muft be hung up and 
taken down every time they are ufed, and the Sup- 
ply by this Method is not conftant. Though Cuftom 
has given a Sanction to this Device, it is fubjed to 
many Inconveniencies: ijl , Each Ship having com- 
* See Dr. Hales's Treatife of Ventilators, 
j See \\ekTranfaffions } N° 437. 
I monly 
