Manufactories. As the steam may be applied to heat the water, and to warm all the apartments.
Paper Mills. The steam may be applied to heat the vats, and warm the drying rooms.
Saw or Grinding Mills, Furnaces, or Forges. As so little water is necessary, that it can be set at the ore banks, or in any convenient place, where a well can be had.
For every other purpose where power may be want ed, there is a difference between this and the low pressure engines, equal to its full price, in a few years use.
Several persons have begun to infringe my rights, having found that what I had published was true; viz. That as the elastic power of steam should be increased, the power of the engine and speed of the boat would be increased, without a proportionate increase of the consumption of fuel.
Some construct and use my specified boiler, in whole, or in part, by using high pressure steam to a condensing engine, to evade my rights. Others have constructed boilers of different forms, which they be lieved to be equally safe and strong : and attempting to use high pressure steam, until they exploded their boilers ; neither of which can succeed perfectly. And they unitedly proclaimed, that it was the invention of high pressure, which caused the injury ; to my very great damage, by depriving me of the profits of my invention, and to the injury of the public, by depriving people of the benefits of the useful discovery. And I am constrained to put the engine of the patent laws of the United States in force and motion, which will probably overtake them.
It would be unpardOnable to omit noticing the steam engine of our ingenious countryman Jacob Perkins, which has excited so much interest in London. " Mr
P.'s original idea of substituting pressure for surface, in generating steam (which appears to be the basis of his invention) if satisfactorily established, must cer tainly be considered as of the utmost importance, par ticularly in its first feature, absolute safety. From the mode of constructing the compound generator (of steam) as now adopted, it becomes a safety valve of itself : for the pressure is divided into so many com partments, that any one of them may explode with impunity, without even disturbing a brick of the fur nace."" Mr. Perkins says " the piston was 8 inches in diameter, with a 20 inch stroke engine, a good 70 horse power, and consuming but one fourth of the coal of a condensing engine. The weight on the end of the lever was 300lbs. To prove the safety of the engine, he says, he has worked it under a pressure of 1400/bs. to the square inch, or at WO atmospheres, and cut off the steam at one twelfth of the stroke. The usual pressure is 8001bs. per inch, cutting off at one eighth, and letting the steam expand to below ioolbs. per inch. He lets off at the dead point, at one flash." As this engine has not yet been introduced into prac tice by any one except the inventor, those who are desirous of a more full account of it are referred to the Franklin Journal, Vol. III. pp. 354, 407; to Gal loway on Steam Engines, p. 185 ; Silliman's Journal, Vol. VII. The two last contain plates of the engine, and in Silliman is an account of the application of Mr. P.'s invention to engines of the old construction.