Watt knew better than any that although his model had been successful and was far beyond the Newcomen engine, it was obvious that it could be improved in many respects—not the least of his reasons for confidence in its final and more complete triumph.
To these possible improvements, he devoted himself for years. The records once again remind us that it was not one invention, but many, that his task involved. Smiles gives the following epitome of some of those pressing at this stage:
Various trials of pipe-condensers, plate-condensers and drum-condensers, steam-jackets to prevent waste of heat, many trials of new methods to tighten the piston band, condenser pumps, oil pumps, gauge pumps, exhausting cylinders, loading-valves, double cylinders, beams and cranks—all these contrivances and others had to be thought out and tested elaborately amidst many failures and disappointments.
There were many others.
All unaided, this supreme toiler thus slowly and painfully evolved the steam engine after long years of constant labor and anxiety, bringing to the task a union of qualities and of powers of head and hand which no other man of his time—may we not venture to say of all time—was ever known to possess or ever exhibited.
When a noble lord confessed to him admiration for his noble achievements, Watt replied, "The public only look at my success and not at the intermediate failures and uncouth constructions which have served me as so many steps to climb to the top of the ladder."
Quite true, but also quite right. The public have no time to linger over a man's mistakes. What concerns is his triumphs. We "rise upon our dead selves (failures) to higher things," and mistakes, recognised as such in after days, make for victory. The man who never makes mistakes never makes anything. The only point the wise man guards is not to make the same mistake twice; the first time never counts with the successful man. He both forgives and forgets that. One difference between the wise man and the foolish one!
It has been truly said that Watt seemed to have divined all the possibilities of steam. We have a notable instance of this in a letter of this period (March, 1769) to his friend, Professor Small, in which he anticipated Trevithick's use of high-pressure steam in the locomotive. Watt said:
I intend in many cases to employ the expansive force of steam to press on the piston, or whatever is used instead of one, in the same manner as the weight of the atmosphere is now employed in common fire engines. In some cases I intend to use both the condenser and this force of steam, so that the powers of these engines will as much exceed those pressed only by the air, as the expansive power of the steam is greater than the weight of the atmosphere. In other cases, when plenty of cold water cannot be had, I intend to work the engines by the force of steam only, and to discharge it into the air by proper outlets after it has done its office.
In these days patents could be very easily blocked, as Watt experienced with his improved crank motion. He proceeded therefore in great secrecy to erect the first large engine under his patent, after he had successfully made a very small one for trial. An outhouse near one of Dr. Roebuck's pits was selected as away from prying eyes. The parts for the new engine were partly supplied from Watt's own works in Glasgow and partly from the Carron works. Here the old trouble, lack of competent mechanics, was again met with. On his return from necessary absences, the men were usually found in face of the unexpected and wondering what to do next. As the engine neared completion, Watt's anxiety "for his approaching doom," he writes, kept him from sleep, his fears being equal to his hopes. He was especially sensitive and discouraged by unforeseen expenditure, while his sanguine partner, Roebuck, on the contrary, continued hopeful and energetic, and often rallied his pessimistic partner on his propensity to look upon the dark side. He was one of those who adhered to the axiom, "Never bid the devil good-morning till you meet him." Smiles believes that it is probable that without Roebuck's support Watt could never have gone on, but that may well be doubted. His anxieties probably found a needed vent in their expression, and left the indomitable do-or-die spirit in all its power. Watt's brain, working at high pressure, needed a safety valve. Mrs. Roebuck, wife-like, very properly entertained the usual opinion of devoted wives, that her husband was really the essential man upon whom the work devolved, and, that without him nothing could have been accomplished. Smiles probably founded his remark upon her words to Robison: "Jamie (Watt) is a queer lad, and, without the Doctor (her husband), his invention would have been lost. He won't let it perish." The writer knows of a business organisation in which fond wives of the partners were all full of dear Mrs. Roebuck's opinion. At one time, according to them, the sole responsibility rested upon three of four of these marvellous husbands, and never did any of the confiding consorts ever have reason to feel that their friend did not share to the fullest extent the highly praiseworthy opinion formed of his partners by their loving wives. The rising smile was charitably suppressed. In extreme cases a suggested excursion to Europe at the company's expense, to relieve Chester from the cruel strain, and enable him to receive the benefit of a wife's care and ever needful advice, was remarkably effective, the wife's fears that Chester's absence would prove ruinous to the business being overcome at last, though with difficulty.