Page:Passages from the Life of a Philosopher.djvu/126

"The latter [its public utility] they consider as obvious to every one who considers the immense advantage of accurate numerical tables in all matters of calculation, especially in those which relate to astronomy and navigation."—Report of the Royal Society, 12th Feb., 1829.

Thus it appears:—

1st. That the Chancellor of the Exchequer presumed to set up his own idea of the utility of the Difference Engine in direct opposition to that of the Royal Society.

2nd. That he refused to take the opinion of the highest mechanical authority in the country on its probable cost, and even to be informed whether a contract for its construction at a definite sum might not be attainable: he then boldly pronounced the expense to be "utterly incapable of being

"calculated."

This much-abused Difference Engine is, however, like its prouder relative the Analytical, a being of sensibility, of impulse, and of power.

It can not only calculate the millions the ex-Chancellor of the Exchequer squandered, but it can deal with the smallest quantities; nay, it feels even for zeros.^[1] It is as conscious as Lord Derby himself is of the presence of a negative quantity, and it is not beyond the ken of either of them to foresee the existence of impossible ones.^[2]

Yet should any unexpected course of events ever raise the

1. It discovers the roots of equations by feeling whether all the figures in a certain column are zeros.
2. It may be necessary to explain to the unmathematical reader and to the ex-Chancellor of the Exchequer that impossible quantities in algebra are something like mare's-nests in ordinary life.