§5

Hydraulics.

Plate

XXV.

(LXXXI.) The Method of constructing a Fire-En-s*ne according to the original Institution of the Mar-ly 113 of JV)rcefter and Capt. Savery , wherein the Water3s to be raised solely by the Pressure of elastic Va-r or Steam, is very useful, and cheap in respect ofyy otll «' Sort; and when the Height, to which theth at6r ! S to raised, does not exceed ioo or 150 Feet,it 611 this Engine is applicable with great Advantage,re quirlng but a small Fire (not bigger than what isand erall y used in a Parlour Chimney) is of a very simpleof Structure, and admirably adapted for playing°uiitains to very great Heights.

£ Hefaguliers has given us the Structure of this

:ir icf f 16 ° n a Copper Plate, with his last Improvements,f 0r -^ ec ause I think this better than that which Profesi-es ■ffl len l> r oek has exhibited in his EJsai de Physique,

Cla 'v for raising Water, I shall here give the said .

^ Ur l^ a nd its Explication. ”

b u j ^be Boiler B B is a large Copper Body of a glo-g ar Eorm, which will best of all withstand the verya t Force of Steam, that is in this Case necessary.

- onnd the Body of this Boiler the Fire and Flame arev e y as shewn at TTT. It has a Copper Co-

and ( ' crcw5 d on, which contains the Steam-Pjpe CD,Ougo-Pipes, N, O, which, by turning theirstrew the Height of the Surface of the Water. u h as in the other Engine,stes 0 n t b e fame Cover at P is a V^alve, over whichSt r£ a ^ tee l-yard with its Weight Qjto keep it down, thee stirn^ t l t ^ le Vapour being this Way most exactlystsirdV^ : Eor being in the Nature of a Lever, of thev 'ded '° rt ’ ,,: ’ s the Beam of the Lever be di-

th e i\/r'- n ,j 0 10 e qual Parts, and the first of them be uponthe ^ of the Valve, and the Weight Q_hangs atthe St* 4th, &c. Divisions, that then the Force of4, w bich can raise up the Valve will be 2, 3,

th e yV, * as gre..t as the Weight. If the Area ofthe 2(j lV ^\0 e , 3 Square Inch, and Qj= 15 Ib. hanging atVa] ve ’ * v js t0 P * s mised by a Steam pushing up theForce of*’ st iew the Steam will then press with the’ 2 Atmospheres, and so on to 10 Atmospheres ;

G 3 but