If there is any such, I claim as a matter of justice, that it be published. The Difference Engine and the Analytical Engine, are questions of pure science. If the Astronomer Royal has maintained that they are either useless or impracticable, then the grounds of that opinion _must_ have been stated, and, if published, the solidity of those grounds might be examined. It now becomes necessary to take a very brief review of the conduct of Government with respect to the Difference Engine. Having contrived and executed a small model of a Difference Engine, I published a very short account of it in a letter to Sir Humphry Davy, in the year 1822. At the wish of the Government I undertook to construct for them an engine on a much larger scale, which should print its results. I continued to work at this Engine until 1834, refusing in the mean time other sources of profitable occupation, amongst which was an office of about 2,500_l._ a-year. Circumstances over which I had no control then caused the work to be suspended. After eight years of repeated applications, and of the most harassing delay, at the end of 1842 the Government arrived at the resolution of giving up the completion of the Difference Engine, on the alleged ground of its expense. In the mean time, new views had opened out to me the prospect of performing purely algebraic operations by means of mechanism. To arrive at so entirely unexpected a result I deemed worthy of any sacrifice, and accordingly spared no expense in procuring every subsidiary assistance which could enable me to attain it. Each successive difficulty was met by new contrivances, and at last I found that I had surmounted all the great difficulties of the question, and had made drawings of each distinct department of the Analytical Engine. Having expended upwards of 20,000_l._ on the experiments and inquiries which had led me to these results, it would not have been prudent to attempt the _construction_ of such an engine. I thought, however, that there were several offices in the appointment of Government for which I was qualified, and to which, under the circumstances, I had some claim. I hoped if I had obtained one of these, by fulfilling its laborious duties for a few years, and by allowing the whole salary to accumulate, that I might then have been able to retire, and adding the money thus earned to my own private resources, that I might yet have enough of life and energy left to _execute_ the Analytical Engine, and thus complete one of the great objects of my ambition.