Watt wrote to his father at Greenock, November, 1774: "The business I am here about has turned out rather successful; that is to say, the fire-engine I have invented is now going, and answers much better than any other that has yet been made." This is as is usual with the Scotch in speech, in a low key and extremely modest, on a par with the verdict rendered by the Dunfermline critic who had ventured to attend "the playhouse" in Edinburgh to see Garrick in Hamlet--"no bad." The truth was that, so pronounced were the results of proper workmanship, coupled with some of those improvements which Watt was constantly devising, the engine was so satisfactory as to set both Boulton and Watt to thinking about the patent which protected the invention. Six of the fourteen years for which it was granted had already passed. Some years would still be needed to ensure its general use, and it was feared that before the patent expired little return might be received. Much interest was aroused by the successful trial. Enquiries began to pour in for pumping engines for mines. The Newcomen had proved inadequate to work the mines as they became deeper, and many were being abandoned in consequence. The necessity for a new power had set many ingenious men to work besides Watt, and some of these were trying to adopt Watt's principles while avoiding his patent. Hatley, one of Watt's workmen upon the trial engine at the Carron works, had stolen and sold the drawings. All this put Boulton and Watt on their guard, and the former hesitated to build the new works intended for the manufacture of steam engines upon a large scale with improved machinery. An extension of the patent seemed essential, and to secure this Watt proceeded to London and spent some time there, busy in his spare moments visiting the mathematical instrument shops of his youth, and attending to numerous commissions from Boulton. A second visit was paid to London, during which the sad intelligence of the death of his dear friend, Dr. Small, reached him. In the bitterness of his grief, Boulton writes him: "If there were not a few other objects yet remaining for me to settle my affections upon, I should wish also to take up my abode in the mansions of the dead." Watt's sympathetic reply reminds Boulton of the sentiments held by their departed friend--that, instead of indulging in unavailing sorrow, the best refuge is the more sedulous performance of duties. "Come, my dear sir," he writes, "and immerse yourself in this sea of business as soon as possible. Pay a proper respect to your friend by obeying his precepts. No endeavour of mine shall be wanting to make life agreeable to you." Beautiful partnership this, not only of business, but also entering into the soul close and deep, comprehending all of life and all we know of death.