HKB
At length he prepared a model, in which he made use of a crank connected with the working beam of the engine, so as to produce the necessary rotary motion.
There was no originality in this application. The crank was one of the most common of mechanical appliances. It was in daily use in every spinning wheel, and in every turner's and knife-grinder's foot-lathe. Watt did not take out a patent for the crank, not believing it to be patentable. But another person did so, thereby anticipating Watt in the application of the crank for producing rotary motion. He had therefore to employ some other method, and in the new contrivance he had the valuable help of William Murdock. Watt devised five different methods of securing rotary motion without using the crank, but eventually he adopted the "Sun-and-planet motion," the invention of Murdock. This had the singular property of going twice round for every stroke of the engine, and might be made to go round much oftener without additional machinery. The invention was patented in February, 1782, five Years after Murdock had entered the service of Boulton and Watt.
Murdock continued for many years busily occupied in superintending the Cornish steam-engines. We find him described by his employers as "flying from mine to mine," putting the engines to rights. If anything went wrong, he was immediately sent for. He was active, quick-sighted, shrewd, sober, and thoroughly trustworthy. Down to the year 1780, his wages were only a pound a week; but Boulton made him a present of ten guineas, to which the owners of the United Mines added another ten, in acknowledgment of the admirable manner in which he bad erected their new engine, the chairman of the company declaring that he was "the most obliging and industrious workman he had ever known." That he secured the admiration of the Cornish engineers may be obvious from the fact of Mr. Boaze having invited him to join in an engineering partnership; but Murdock remained loyal to the Birmingham firm, and in due time he had his reward.
He continued to be the "right hand man" of the concern in Cornwall. Boulton wrote to Watt, towards the end of 1782: "Murdock hath been indefatigable ever since he began. He has scarcely been in bed or taken necessary food. After slaving night and day on Thursday and Friday, a letter came from Wheal Virgin that he must go instantly to set their engine to work, or they would let out the fire. He went and set the engine to work; it worked well for the five or six hours he remained. He left it, and returned to the Consolidated Mines about eleven at night, and was employed about the engines till four this morning, and then went to bed. I found him at ten this morning in Poldice Cistern, seeking for pins and castors that had jumped out, when I insisted on his going home to bed."
On one occasion, when an engine superintended by Murdock stopped through some accident, the water rose in the mine, and the workmen were "drowned out." Upon this occurring, the miners went "roaring at him" for throwing them out of work, and threatened to tear him to pieces. Nothing daunted, he went through the midst of the men, repaired the invalided engine, and started it afresh.
When he came out of the engine-house, the miners cheered him vociferously and insisted upon carrying him home upon their shoulders in triumph!