Page:Passages from the Life of a Philosopher.djvu/466

450 severest sacrifices of fortune, and even of feelings, in order to accomplish my imagined mission.

The great principles on which the Analytical Engine rests have been examined, admitted, recorded, and demonstrated. The mechanism itself has now been reduced to unexpected simplicity. Half a century may probably elapse before any one without those aids which I leave behind me, will attempt so unpromising a task. If, unwarned by my example, any man shall undertake and shall succeed in really constructing an engine embodying in itself the whole of the executive department of mathematical analysis upon different principles or by simpler mechanical means, I have no fear of leaving my reputation in his charge, for he alone will be fully able to appreciate the nature of my efforts and the value of their results.

In 1824 Arago published his experiments on the magnetism manifested by various substances during rotation. I was much struck with the announcement, and immediately set up some apparatus in my own workshop in order to witness the facts thus announced.

My friend Herschel, who assisted at some of the earliest experiments, joined with me in repeating and varying those of Arago. The results were given in a joint paper on that subject, published in the "Transactions of the Royal Society" in 1825.

I had previously made some magnetic experiments on a large magnet which would, under peculiar management, sustain about 32½ lbs. It was necessary to commence with a weight of about 28 lbs., and then to add at successive intervals additional weights, but each less and less than the former.