Tunnels and Tunnelling.

Train on Brunel's South Devon atmospheric railway showing, between the rails, the 2-ft diameter vacuum pipe used for propulsion. The top of the pipe had a lengthwise slit, sealed with leather flaps. A strong arm attached to the carriage passed under the flaps and through the slit to a piston inside the bore. When a powerful pump ahead of the train reduced the air pressure in the tube, atmospheric pressure on the trailing side of the piston pushed it and the train forward. (source)

A French engineer, M. Favre1, has recently proposed the construction of a tunnel under the waters of the Straits of Dover, to unite France and England, by a subterranean railway. Surveys of the route have been made; every foot of the English channel has been sounded, and recent English papers assert the practicability of the project. Its length, under water will be nineteen miles; and the entrances on land, to obtain the proper grade, will be about two miles long, making a total length of about twenty-one miles. Its walls are intended to be very thick, composed of huge granite blocks cemented together, and lined with a circular shield of perforated iron plates.

The railroad through it is intended to be operated by stationary engines, which are to drive the trains by compressed air, and thus avoid the heat and smoke, which would be entailed by the use of locomotives. In excavating this tunnel, M. Favre proposes to get rid of the excavations in a most ingenious and economical manner. The plan consists in building strong tall air shafts or chimneys for ventilation along its course, through which the excavated materials shall be lifted and thrown into the sea, forming little islands around the shafts, thus protecting them from the action of the waves. The whole cost of this great work, it is stated, will amount to but $10,000,000. In an article on this subject, in the New York Times of the 13th inst., we find the following remarks :—

The idea of tunnelling the river Thames is probably due to Ralph Dodd, a painter by trade, but an able amateur engineer, who proposed to construct a tunnel under the Thames at Gravesend, in 1798; and in 1807 Trevithick, the engineer, was employed to sink a shaft and commence a tunnel at Rotherhithe, in London, but the water and quicksand broke in upon his excavation and defeated his operations. The project was then abandoned until 1823, when a company was formed to carry out Brunel’s plan, which, after some reverses, was accomplished, and the Tunnel opened in 1843—twenty years after the company was formed. This tunnel is but 400 yards in length, yet it cost, from first to last, $2,273,000, while its annual receipts only amount to about $25,000.

Another engineer, Henry Mulliner, also proposes to construct a tunnel of huge iron tubes, made in sections, bolted and cemented together, and laid down in the Channel between France and England. He asserts that the bottom of the Dover Straits is suitable (it must be level for this purpose,) and that such a tunnel will be much cheaper than one which has to be excavated under the bed of the sea.

This plan looks far more feasible than the one suggested by Favre; but we have no idea that the Tunnel between France and England (eighty-three times the length of the Thames Tunnel) can be constructed for ten or twice ten million of dollars, taking the expense of the Thames Tunnel as a basis. Tunnels are the most expensive works of railroad engineering; and, like bridges, their expense increases in a quadruple ratio, according as their length is increased. This fact should not escape the attention of engineers when they enter into calculations upon enterprises of such magnitude.

Nature bears long with those who wrong her. She is patient under abuse. But when abuse has gone too far, when the time of reckoning finally comes, she is equally slow to be appeased and to turn away her wrath. (1882) -- Nathaniel Egleston, who was writing then about deforestation, but speaks equally well about the danger of climate change today.

Carl Sagan: In science it often happens that scientists say, 'You know that's a really good argument; my position is mistaken,' and then they would actually change their minds and you never hear that old view from them again. They really do it. It doesn't happen as often as it should, because scientists are human and change is sometimes painful. But it happens every day. I cannot recall the last time something like that happened in politics or religion. (1987) ...(more by Sagan)

Albert Einstein: I used to wonder how it comes about that the electron is negative. Negative-positive—these are perfectly symmetric in physics. There is no reason whatever to prefer one to the other. Then why is the electron negative? I thought about this for a long time and at last all I could think was “It won the fight!” ...(more by Einstein)

Richard Feynman: It is the facts that matter, not the proofs. Physics can progress without the proofs, but we can't go on without the facts ... if the facts are right, then the proofs are a matter of playing around with the algebra correctly. ...(more by Feynman)

Quotations by: • Albert Einstein • Isaac Newton • Lord Kelvin • Charles Darwin • Srinivasa Ramanujan • Carl Sagan • Florence Nightingale • Thomas Edison • Aristotle • Marie Curie • Benjamin Franklin • Winston Churchill • Galileo Galilei • Sigmund Freud • Robert Bunsen • Louis Pasteur • Theodore Roosevelt • Abraham Lincoln • Ronald Reagan • Leonardo DaVinci • Michio Kaku • Karl Popper • Johann Goethe • Robert Oppenheimer • Charles Kettering  ... (more people)

Quotations about: • Atomic  Bomb • Biology • Chemistry • Deforestation • Engineering • Anatomy • Astronomy • Bacteria • Biochemistry • Botany • Conservation • Dinosaur • Environment • Fractal • Genetics • Geology • History of Science • Invention • Jupiter • Knowledge • Love • Mathematics • Measurement • Medicine • Natural Resource • Organic Chemistry • Physics • Physician • Quantum Theory • Research • Science and Art • Teacher • Technology • Universe • Volcano • Virus • Wind Power • Women Scientists • X-Rays • Youth • Zoology  ... (more topics)