plied to Carts; and in 1813 he
published an essay on Roads, and Wheel Carriages. His daughter
writes:--'In the course of the drudgery which he went through he
received a great counterbalancing pleasure from the following
passage, which he chanced to meet with in a letter to the committee,
written by a gentleman to whom he was personally a stranger:

'"Mr. Edgeworth was the first who pointed out the great benefit of
springs in aiding the draught of horses. The subject deserves more
attention than it has hitherto met with. No discovery relative to
carriages has been made in our time of equal importance; and the
ingenious author of it deserves highly of some mark of public
gratitude."'

Maria adds:--'Those ingenious ideas, which had been but the
amusement of youth, as he advanced in life, he turned to public
utility: for instance, the mode of conveying secret and swift
intelligence, which he had suggested at first only to decide a
trifling wager between him and some young nobleman, he afterwards
improved into a national telegraph, and through all difficulties and
disappointments persevered till it was established. In the same
manner, his juvenile amusements with the sailing chariot led to
experiments on the resistance of the air, which in more mature years
he pursued in the patient spirit of philosophical investigation, and
turned to good account for the real business of life, and for the
advancement of science.

'On this subject, in the year 1783, he published in the Transactions
of the Royal Society (vol. 73) "An Essay on the Resistance of the
Air," of which the object, as he states, is to determine the force
of the wind upon surfaces of different size and figure, or upon the
same surface, when placed in different directions, inclined at
different angles, or curved in different arches. . . . After trying
several experiments on surfaces of various shapes, he ascertained
the difference of resistance in different cases, suggested the
probable cause of these variations, and opened a large field for
future curious and useful speculation; useful it may be called, as
well as curious, because such knowledge applies immediately to the
wants and active business of life, to the construction of wind- and
water-mills, and to the extensive purposes of navigation. The theory
of philosophers and the practice of mechanics and seamen were, and
perhaps are still, at variance as to the manner in which sails of
wind-mills and of ships s