Wilkinson wants an engine to raise a stamp of 15 cwt. thirty or forty times in a minute. I have set Webb to work to try it with the little engine and a stamp-hammer of 60 lbs. weight. Many of these _battering rams_ will be wanted if they answer. The trial was successful. A new machine to work a 700 lbs. hammer for Wilkinson was made, and April 27, 1783, Watt writes that it makes from 15 to 50, and even 60, strokes per minute, and works a hammer, raised two feet high, which has struck 300 blows per minute. The engine was to work two hammers, but was capable of working four of 7 cwt. each. He says, with excusable pride, I believe it is a thing never done before, to make a hammer of that weight make 300 blows per minute; and, in fact, it is more a matter to brag of than for any other use, as the rate wanted is from 90 to 100 blows, being as quick as the workmen can manage the iron under it. This most ingenious application of steam power was included in Watt's next patent of April 28, 1784. It embraced many improvements, mostly, however, now of little consequence, the most celebrated being "parallel motion," of which Watt was prouder than any other of his triumphs. He writes to his son, November, 1808, twenty-four years after it was invented (1784): Though I am not over anxious after fame, yet I am more proud of the parallel motion than of any other mechanical invention I have ever made. He wrote Boulton, in June, 1784: I have started a new hare. I have got a glimpse of a method of causing a piston-rod to move up and down perpendicularly, by only fixing it to a piece of iron upon the beam ... I think it one of the most ingenious simple pieces of mechanism I have contrived. October, 1784, he writes: The new central perpendicular motion answers beyond expectation, and does not make the shadow of a noise. He says: When I saw it in movement, it afforded me all the pleasure of a novelty, as if I had been examining the invention of another. When beam-engines were universally used for pumping, this parallel motion was of great advantage. It has been superseded in our day, by improved piston guides and cross-heads, the construction of which in Watt's day was impossible, but no invention has commanded in greater degree the admiration of all who comprehend the principles upon which it acts, or who have witnessed the smoothness, orderly power and "sweet simplicity" of its movements. Watt's pride in it as his favorite invention in these respects is fully justified. A detailed specification for a road steam-carriage concludes the claims of this patent, but the idea of railroads, instead of common roads, coming later left the construction of the locomotive to Stephenson.[1] Watt's last patent bears date June 14, 1785, and was