In the mean time Trevithick occupied himself in carrying on the various business of a general engineer, and was ready to embark in any enterprise likely to give scope for his inventive skill. In whatever work he was employed, he was sure to introduce new methods and arrangements, if not new inventions. He was full of speculative enthusiasm, a great theorist, and yet an indefatigable experimenter. At the beginning of 1806--the year after the locomotive had been taken off the Merthyr Tydvil tram-road--he made arrangements for entering into a contract for ballasting all the shipping in the Thames. At the end of a letter written by him on the 18th of February in that year to Davies Gilbert, respecting a _puffer_ engine, he said, "I am about to enter into a contract with the Trinity Board for lifting up ballast out of the bottom of the Thames for all the shipping. The first quantity stated was 300,000 tons a year, but now they state 500,000 tons. I am to do nothing but wind up the chain for 6_d._ per ton, which is now done by men. They never lift it above twenty-five feet high--a man will now get up ten tons for 7_s._ My engine at Dalcoath has lifted about 100 tons that height with one bushel of coals. I have two engines already finished for the purpose, and shall be in town in about fifteen days for to set them to work. They propose to engage with me for twenty-one years."[16] The contract was not, however, entered into. Trevithick quarreled with the capitalists who had found the money for the trials, and the "Blazer" and "Plymouth," the vessels in which his engines and machinery had been fitted, fell into other hands. Trevithick, nevertheless, seems to have been on the highway to fortune, for, at the beginning of 1806, he had received orders for nine engines in one month, all for Cornwall; and he expected orders for four others. He had also in view the construction of a railway; but nothing came of this project. More hopeful still, as regarded immediate returns, was the Cornish engine business, which presented a very wide field. Now that the trade had been thrown open by the expiry of Boulton and Watt's patent, competition had sprung up, and many new makers and inventors of engines were ready to supply the demand.