After reflecting for some time upon all this, it at last occurred to Watt to consider whether it might not be possible, instead of continuing to condense the steam in the cylinder, to contrive that method of drawing it off, to undergo that operation in some other vessel. This fortunate idea having presented itself to his mind, it was not long before his ingenuity suggested to him the means of realising it. In the course of one or two days, according to his own account, he had all the necessary apparatus arranged in his mind. The plan which he devised was, indeed, an extremely simple one, and on that account the more beautiful. He proposed to establish a communication by an open pipe, between the cylinder and another vessel, the consequence of which evidently would be, that when the steam was admitted into the former, it would flow into the other to fill it also. If, then, the portion in this latter vessel only should be subjected to a condensing process, by being brought into contact with cold water, or any other convenient means, what would follow? Why, a vacuum would be produced here--into that, as a vent, more steam would immediately rush from the cylinder--that likewise would be condensed--and so the process would go on till all the steam had left the cylinder, and a perfect vacuum had been effected in that vessel, without so much as a drop of cold water having touched or entered it. The separate vessel alone, or the condenser, as Watt called it, would be cooled by the water used to condense the steam--and that, instead of being an evil, manifestly tended to promote and quicken the condensation. When Watt reduced his views to the test of experiment, he found the result to answer his most sanguine expectations. The cylinder, although emptied of its steam for every stroke of the piston as before, was now constantly kept at the same temperature with the steam (or 212 deg. Fahrenheit); and the consequence was, that one-fourth of the fuel formerly required, sufficed to feed the engine. But besides this most important saving in the expense of maintaining the engine, its power was greatly increased by the most perfect vacuum produced in the new construction, in which the condensing water, being no longer admitted within the cylinder, could not, as before, create new steam there while displacing the old.