I have already given the changed use of the word perambulator.  As an example of the different use of a word in the last century, I may mention telegraph, by which he means signalling either by moving wooden arms or by showing lights.  This mode of conveying a message he first applied in order to win a wager:  ’A famous match was at that time pending at Newmarket between two horses that were in every respect as nearly equal as possible.  Lord March, one evening at Ranelagh, expressed his regret to Sir Francis Delaval that he was not able to attend Newmarket at the next meeting.  “I am obliged,” said he, “to stay in London; I shall, however, be at the Turf Coffee-house; I shall station fleet horses on the road to bring me the earliest intelligence of the event of the race, and I shall manage my bets accordingly.”

’I asked at what time in the evening he expected to know who was winner.  He said about nine in the evening.  I asserted that I should be able to name the winning horse at four o’clock in the afternoon.  Lord March heard my assertion with so much incredulity, as to urge me to defend myself; and at length I offered to lay five hundred pounds that I would in London name the winning horse at Newmarket at five o’clock in the evening of the day when the great match in question was to be run.’

The wager was however given up when Edgeworth told Lord March that he did not depend upon the fleetness or strength of horses to carry the desired intelligence.

His friend, Sir Francis Delaval, immediately put up under his directions an apparatus between his house and part of Piccadilly.  He adds:  ’I also set up a night telegraph between a house which Sir Francis Delaval occupied at Hampstead, and one to which I had access in Great Russell Street, Bloomsbury.  This nocturnal telegraph answered well, but was too expensive for common use.’  Later on he writes to Dr. Darwin: 

’I have been employed for two months in experiments upon a telegraph of my own invention.  By day, at eighteen or twenty miles distance, I show, by four pointers, isosceles triangles, twenty feet high, on four imaginary circles, eight imaginary points, which correspond with the figures 0, 1, 2, 3, 4, 5, 6, 7, so that seven thousand different combinations are formed, of four figures each, which refer to a dictionary of words.  By night, white lights are used.’

Dr. Darwin in reply says:  ’The telegraph you described, I dare say, would answer the purpose.  It would be like a giant wielding his long arms and talking with his fingers:  and those long arms might be covered with lamps in the night.’

It is curious now to read Mr. Edgeworth’s words:  ’I will venture to predict that it will at some future period be generally practised, not only in these islands, but that it will in time become a means of communication between the most distant parts of the world, wherever arts and sciences have civilised mankind.’