Scientific discovery, or at any rate the practical application of scientific truths to the ordinary needs of life, had made considerable progress since the accession of Queen Victoria, and it may be convenient at this stage to review some of the principal changes thus effected. Electric Telegraph was probably of more importance than any other. The active powers of the electric “fluid” had been known for many years, and some of the greatest inquirers of modern times had anticipated extraordinary results from an agency so potent, and so various in its operations. The transmission of electricity by an insulated wire was shown by several experimenters as early as 1747, and in later years telegraphic arrangements were devised by scientific explorers, both English and foreign. But no very decided progress in the transmission of thought by electricity was effected until a short period before the death of William IV., when somewhat analogous plans were simultaneously conceived in England and America by Professor Wheatstone and Professor Morse. It has sometimes been a matter of contention as to whether the honour of this discovery should belong to the one or the other; but it may in truth be fairly divided between both. The first telegraphic line in England was set up by Mr. (afterwards Sir William) Cooke, on the Great Western Railway, between Paddington and West Drayton, in 1838-9. The first telegraphic line in America was not constructed until 1844. From those respective dates, the new means of intercommunication spread rapidly on both sides of the Atlantic, until, in these days, the whole civilised world is covered with a mesh of telegraphic lines, almost as wonderful in their operation as the web of nerves which, in the living animal, carry the conceptions of the brain through every part of the system, and the impression of the senses to the seat of reason. One of the earliest practical applications of the new telegraphic system, in a matter concerning the general interests of the public, occurred at the commencement of 1845. On the 1st of January a woman was murdered at Salt Hill, near Slough, and a certain Quaker with whom she had been intimate was suspected of the crime. The man made his way to Slough, and proceeded by train to London; but a telegraphic description of his appearance, and a statement of the reasons for his detention, had reached Paddington before the time of his arrival. A policeman was waiting on the platform, and the suspected person was closely watched and followed until it was considered prudent to arrest him. He was tried, found guilty, and executed; and Sir Francis Head, the well-known writer, records that while travelling on the same railway some time afterwards, he heard a third-class passenger, pointing to the telegraph lines, remark, “Them’s the cords that hanged John Tawell.”