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become in its nature a part of the boiler itſelf; and after all, would prove inadequate, even though it was placed over the mouth of an Etna or a Veſuvius. The jet of cold water Mr. Watt has contrived to ſmuggle into this curious condenſer (contrary to what he intended when he took his patent) muſt be always equal with the help of his ſurrounding jacket (which may be of water or any thing elſe) to condenſe or deſtroy the ſteam’s force even in its way to the condenſer.
Secondly. There is, as your Lordſhip has been abundantly informed, a valve placed in the paſſage allotted to conduct the ſteam, water, &c. from the cylinder to the condenſer, which alternately opens and ſhuts this communication. I have to remark, that when the ſteam regulator, as in Newcomen’s Engine, opens to the cylinder, and at the ſame time cauſes the firſt jet of ſteam to diſcharge the water and air as above deſcribed, this valve, in Mr. Watt’s Engine, is then open to the condenſer; and was there nothing elſe, the ſteam would, as well as act on the piſton, fly to the condenſer, and being there deſtroyed at that end, if I may ſo fay, would not move the piſton at all. It was therefore ne-
ceſſary
