In a subsequent letter Watt promised Small that he would pay an early visit to Birmingham, and added, “there is nowhere I so much wish to be.” In replying, Small pointed out a difficulty in the way of the proposed partnership: “It is impossible,” he wrote, “for Mr. Boulton and me, or any other honest man, to purchase, especially from two particular friends, what has no market price, and at a time when they might be inclined to part with the commodity at an under value.”[128] He added that the high-pressure wheel-engine constructing at Soho, after Watt’s plans, was nearly ready, and that Wilkinson, of Bradley, had promised that the boiler should be sent next week. “Should the experiment succeed, or seem likely to succeed,” he said, “you ought to come hither immediately upon receiving the notice, which I will instantly send. In that case we propose to unite three things under your direction, which would altogether, we hope, prove tolerably satisfactory to you, at least until your merit shall be better known.”[129] [127] Watt to Small, 30th August, 1772. Boulton MSS. [128] Small to Watt, 16th November, 1772. Boulton MSS. [129] About this time, in order to bring himself and his engine into notice, Watt contemplated writing a treatise on steam and its applications. “I have some thoughts,” he wrote to Small, “of writing a book on the elements of the theory of steam-engines, in which, however, I shall only give the enunciation of the perfect engine. This book might do me and the scheme good. It would still leave the world in the dark as to the true construction of the engine. Something of this kind is necessary, as Smeaton is labouring hard at the subject, and if I can make no profit, at least I ought not to lose the honour of my experiments.”--Watt to Small, 17th August, 1773. Boulton MSS. To this letter Small replied, “The more I consider the propriety of your publishing about steam, the more I wish you to publish. Smeaton has only trifled hitherto, though he may perhaps discover something. He told Boulton some time ago that the circular engine would not do. He said he had considered it, and was sure of this. As B. does not much respect his genius, this had no effect.” Watt’s treatise was, however, never written; his attention being shortly after fully occupied by other and more engrossing subjects.