But what grieved me most was, that to the last, your poor father was struggling above his strength against difficulties which he well knew might have been removed, if it had not been attended with too much expense. The last time the mirror was obliged to be taken from the polisher on account of some obstacle, I heard him say (in his usual manner of thinking aloud on such occasions), “It is impossible to make the machine act as required without a room three times as large as this.” But when all hope for the return of vigour and strength necessary for resuming the unfinished task was gone, all cheerfulness and spirits had also forsaken him, and his temper was changed from the sweetest almost to a pettish one; and for that reason I was obliged to refrain from troubling him with any questions, though ever so necessary, for fear of irritating or fatiguing him; else there was work enough cut out for keeping me employed for several years to come, such as making correct registers of the sweeps in which all Nebulæ were to be laid down and numbered, complete Catalogues, &c. But what I most regret is, that I never could find an opportunity of consulting your father about collecting the observations made with the 40-foot into a separate book from the journals, into which they were written down among other observations made with the other instruments in the same night. I know besides that many must have been lost, being noted only either on slates or on loose papers, like those on the first discovery of the Georgian Satellites. Owing to my not being, as formerly, the last nor the first at the desk (generally retiring as soon as the mirror was covered), the memorandums were often mislaid or effaced before I had an opportunity of booking them. But I ought to remember that suchlike incomplete observations were made under unfavourable circumstances. For instance, the P. D. clock disordered by not having been used for some time; the timepiece not having been regulated, nor _every one_ of the out-door motions wanting oiling or cleaning; company being present; the night not perfectly clear; and, in general, the first night the instrument is used after it has been left at rest for some time, it cannot be expected that all should go on without interruption or ease without a good mechanical workman had spent best part of the day in looking over all the motions, in doing which your father used to find great pleasure. But what I most lament is, that between the interval before your coming to the age of forming a proper opinion of the instrument, it had nearly fallen into decay almost in all its parts. But we have all had the grief to see how every nerve of the dear man had been unstrung by over-exertion; and that a farther attempt at leaving the work complete became impossible.