[ [263] The parallel motion was first put in practice in the engine erected for Mr. Whitbread; Watt informing Boulton (27th October, 1785) that “the parallel motion of Whitbread’s answers admirably.”
[ [264] ‘Lives of Engineers,’ iii. 77.
[ [265] In a letter dated 28th August, 1784, Watt communicated his views to his partner on the subject of locomotive engines at great length. In the course of the letter he says,—
“My original ideas on this subject were prior to my invention of the improved engines, or before the crank or any other rotative motions were thought of. My plan then was to have two inverted cylinders with toothed racks instead of piston rods, which were to be applied to the ratchet wheels on the axletree, and to act alternately; and I am partly of opinion that this method might be applied with advantage yet, because it needs no fly, and has other conveniences.
“From what I have said, and from much more which a little reflection will suggest to you, you will see that without several circumstances turn out more favourable than has been stated, the machine will be clumsy and defective, and that it will cost much time to bring it to any tolerable degree of perfection; and that for me to attempt to interrupt the career of my business to bestow any attention to it, would be imprudent. I even grudge the time I have taken to write these comments on it.”
[ [266] Boulton to Watt, 8th November, 1784. Though Murdock was thus occupied, he did not abandon his idea of making a working locomotive. Two years later we find Watt thus writing Boulton:—
“I am extremely sorry that W. Murdock still busies himself with the steam carriages. In one of my specifications I have secured it, as well as words could do, according to my idea of it, and if to that you add Symington’s and Sadler’s patents, it can scarcely be patentable, even if free of the general specification in the Act of Parliament; for even granting that what I have done cannot secure it, yet it can act as a prior invention against anybody else; and if it cannot be secured by patent, to what purpose should anybody labour at it? I have still the same opinions concerning it that I had, but to prevent as much as possible more fruitless argument about it, I have one of some size under hand, and am resolved to try if God will work a miracle in favour of these carriages. I shall in some future letter send you the words of my specification on that subject. In the mean time I wish William could be brought to do as we do, to mind the business in hand, and let such as Symington and Sadler throw away their time and money in hunting shadows.”—Watt to Boulton, 12th Sept., 1786. In a subsequent letter, Watt expresses himself as much gratified to learn “that William applies to his business.”
[ [267] Boulton to Wilson, 16th December, 1784. Boulton MSS.
[ [268] Watt to Boulton, 31st March, 1785.
[ [269] Watt to Boulton, 21st July, 1785. Writing to Boulton on a later occasion on the subject of these threatened attacks on all patents, he said, “A pursuance of such decisions as have been given lately in several cases must at length drive men of invention to take shelter in countries where their ingenuity will be protected; and the other states of Europe know their interest too well to neglect any opportunity of curbing the insolence and humbling the pride of Britain. If the minister should not think it right to amend and confirm the patent laws, the next best thing would be to make a law totally taking away the king’s power of granting them. I mean, this would be the honest part.”—Watt to Boulton, 19th March, 1786. Boulton himself had equally strong views on the subject of patents, believing that they tended to encourage industrious and ingenious men to labour for the common good. Referring to the decision against Argand’s lamp patent, he wrote De Luc in 1787,—“It was hard, unjust, and impolitic, as it hath (to my knowledge) discouraged a very ingenious French chemist from coming over and establishing in this country an invention of the highest importance to one of our greatest manufactures. Moreover, it tends to destroy the greatest of all stimulants to invention, viz. the idea of enjoying the fruits of one’s own labour. Some late decisions against the validity of certain patents have raised the spirits of the illiberal, sordid, unjust, ungenerous, and inventionless misers, who prey upon the vitals of the ingenious, and make haste to seize upon what their laborious and often costly application has produced. The decisions to which I refer have encouraged a combination in Cornwall to erect engines on Boulton and Watt’s principles, contrary to the Law of Patents and the express provisions of an Act of Parliament; and this they are setting about in order to drive us into a court of law, flattering themselves that it is the present disposition of the judges to set their faces against all patents. Should such a disposition (so contrary to Lord Mansfield’s decisions) continue to prevail, it will produce far greater evils to the manufacturing industry of the kingdom than the gentlemen of the law can have any idea of.”