Ampere developed the idea of Laplace into a definite plan, and in 1830 or thereabout Ritchie, in London, and Baron Schilling, in St. Petersburg, exhibited experimental models. In 1833 and afterwards Professors Gauss and Weber installed a private telegraph between the observatory and the physical cabinet of the University of Gottingen. Moreover, in 1836 William Fothergill Cooke, a retired surgeon of the Madras army, attending lectures on anatomy at the University of Heidelberg, saw an experimental telegraph of Professor Moncke, which turned all his thoughts to the subject. On returning to London he made the acquaintance of Professor Wheatstone, of King's College, who was also experimenting in this direction, and in 1836 they took out a patent for a needle telegraph. It was tried successfully between the Euston terminus and the Camden Town station of the London and North-Western Railway on the evening of July 25th, 1837, in presence of Mr. Robert Stephenson, and other eminent engineers. Wheatstone, sitting in a small room near the booking-office at Euston, sent the first message to Cooke at Camden Town, who at once replied. "Never," said Wheatstone, "did I feel such a tumultuous sensation before, as when, all alone in the still room, I heard the needles click, and as I spelled the words I felt all the magnitude of the invention pronounced to be practicable without cavil or dispute." The importance of the telegraph in working railways was manifest, and yet the directors of the company were so purblind as to order the removal of the apparatus, and it was not until two years later that the Great Western Railway Company adopted it on their line from Paddington to West Drayton, and subsequently to Slough. This was the first telegraph for public use, not merely in England, but the world. The charge for a message was only a shilling, nevertheless few persons availed themselves of the new invention, and it was not until its fame was spread abroad by the clever capture of a murderer named Tawell that it began to prosper. Tawell had killed a woman at Slough, and on leaving his victim took the train for Paddington. The police, apprised of the murder, telegraphed a description of him to London. The original "five needle instrument," now in the museum of the Post Office, had a dial in the shape of a diamond, on which were marked the letters of the alphabet, and each letter of a word was pointed out by the movements of a pair of needles. The dial had no letter "q," and as the man was described as a quaker the word was sent "kwaker." When the tram arrived at Paddington he was shadowed by detectives, and to his utter astonishment was quietly arrested in a tavern near Cannon Street.