De Machina Hydravl. Londinensi. §3

most consumed. Now when there is need of doing

this,turn the Cock E fb, that there can be no commu-nication between the Force Pipe S, and the lesser Boy-ler D, and putting in a little Fire, at B 1 , the Water the-re wiii grow prelently hotj and when it boils, itsownSteam, which hath no vent out, preffing on itssurface,will force the Water up the Pipe H, trough K, intothe great Boyler L, and so long will it run, till the sur-sae«? of the Water in the Boyler D, get to be as low,as tke böttora of the Pipe H,and then the Steam andWater will run together, and by its Noise and Radingof the Clack hwill giue him that worcks the Engine',sufficient assurance, that D hath emptied and dischar-ged it self into L, and carried in as much Water, as isthen necessary, aster which by turning the Cock I a-eain, you may let new cold Water out pfS into Dthelesser Boiler as before : and thus will there be a con-stant t motion, and a cpntinual supply of the Engine,without fear of Decay or disorder.

Also to know whether L want replenishing. or not,you needonly turn the Cock N, and if Water comeout, there is no need to replenish* but if Steam onlycome, you may conclude, there is. And the like willthe Cock G do, in reference to the lesser Boyler D,shewing when tis necessary to sypply that with freshwater from 8, so that in working the Engine there isvery little Skill or labour required, it being only tabe injured by either a stupid, or wilful negkcl of theUfes and application of this Engine, the Reader willfind a füll account in the Inventors Book calied theMiners Friend.