The tunnel through the Blue Ridge, in Virginia, is 4,273 feet long, and 700 feet below the top of the mountain ; on this account it was thought expedient to construct without shafts. This tunnel slopes from west to east, at the rate of 70 feet to the mile, so that, on the west side, the water, which proved very abundant and troublesome, had to be removed by artificial means. For some distance at the entrance I determined to introduce a siphon of unusual length, which proved a difficult, and, at the same time, interesting experiment. The whole length of the siphon is 1,792 feet, viz., 563 feet inside of the tunnel, and 1,229 feet outside. The level of the water inside is upward of 9 feet below the summit, and the fall outside 29J feet, so that the head is a fraction over 20 feet. Iron faucet pipes of three inches interior diameter were adopted. It was feared that larger ones would carry along too much air ; and that the siphon would have to be fed too often at the summit, an apprehension which the results observed seem to justify. A common faucet cock is placed at each end, to close the siphon when it becomes necessary to fill it again with water; and at the summit a large air vessel is provided to collect the air disengaged from the water, with a suitable opening at top, to let the air out and replace it with water ; this opening being closed by a cap tightly screwed down. At the bottom of the air vessel there is, besides, a large cock, which is closed while the siphon is being fed through the top opening, so as not to interrupt the running of the siphon during the operation. The annexed diagram represents the air vessel,a ; b is the cap ; e the cut-off cock ; e the main pipe or siphon ; d is a glass tube for observing the level of the water. This, however, being often broken was dispensed with at last; the level of the water being easily ascertained by knocking against the air vessel. Things being now disposed as described, it might be supposed that the discharge would have gone on uninterruptedly, requiring only a careful attention to replenish occasionally with water the air vessel; but such was not the case ; at first the joints had been made tight by packing with oakum and then thickly pitched over. The siphon was filled with water through the air vessel, which, being then closed and the ends open, the water began to flow ; but this did not continue for more than five or ten minutes, when the air vessel was found empty of water, and had to be replenished at these short intervals ; moreover, notwithstanding this tedious repetition of feeding the siphon, it would ultimately run dry in about two hours. This was a truly discouraging circumstance ; we ascribed it to the fact that, there being upwards of 200 joints, air was introduced in small bubbles through the oakum packing by the external pressure at every joint, and that it accumulated rapidly all along, especially in the longer arm of the siphon, which soon became too light. Accordingly, we decided not to abandon the enterprise, but to caulk the joints with lead in the usual way, which was not done before for motives of economy, and because, it being only a temporary fixture, it would have been more easily taken apart. This operation was not entirely successful, though the caulking was made so hard that many of the bells broke in packing, without making the joints perfectly impermeable. Then a cement was made of equal parts of white lead and red lead mixed to the consistency of soft putty, with equal quantities of Japan varnish and boiled linseed oil. This cement carefully coated over the joints, made them at last perfectly tight. The siphon thus improved runs now regularly. Still the air vessel must be replenished with water every two hoars, which is done by a pipe leading from a spring ; and moreover, every six hours the ends must be closed, and the whole siphon filled in anew with water; otherwise it would run dry. It is probable that, owing to its being so long, and consequently so level, bubbles of air travel along very slowly and increase in size gradually ; possibly some air may find its way under external pressure through the iron itself. A curious circumstance took place in the beginning; the tunnel having progressed much beyond the well of the siphon, and the water considerably increased, a horse-power with chain pumps was constructed at the further end to pump up the water into troughs, by which it is led to the siphon well Here, the siphon being insufficient for this accession of water, another horse-power was introduced to pump up water out of the same well. As soon, however, as the chain pumps began to revolve in the well, the siphon suddenly stopped and we were obliged to dig a separate woll for it ; since which time both have worked well. The siphon, by actual measurement, when just replenished, discharges 43i gallons per minute, whereas all known formula; give between 54 and CO gallons, and furthermore, in Weale's "Engineers' and Contractors' Companion" occurs this conflicting remark taken from R. A. Peacocke's work : " By Dr. Young's formula (considered by him the best), a 5-inch pipe would be used where a 3-J would suffice ; a 7-inch where a 5 would suffice ; a 10 inch where a 7 would suffii-e, and a 14-inch where a 10 would suffice." And then he goes on to show the useless expenditure resulting from pipes too large being used in obedience to these formula?. But here, in this extraordinary long siphon, his opinion is not sustained, and wo find, on tin: contrary, the discharge is less than the formula; given, and that neither they nor Mr. Peacocke's rules are applicable to this case;. The siphon I have described is, I believe, this longest evor attempted to be used, and on this account the results ami anomalies it presents are somewhat interesting. It certainly has rendered considerable service in the Blue Uidge Tunnel ; with no other current expense than the employment of a man to attend to the air vessel.—By Col. Claudius C'rozet, C. K., in the Journal of the Franklin Institute. A Cliinaman on the Chinese Question. Whatever may be the average intellect of the Chinese, there can be no doubt as to the intellect of the man who made the following speech. The remarks were delivered by Choy Chew, a Chinese merchant, at a recent banquet in Chicago : " Eleven years ago I came from my home in China to seek my fortune in your great Republic. I landed on the golden shore of California, utterly ignorant of your language, unknown to any of your people, a stranger to your customs and laws, and in the minds of some an intruder—one of that race whose presence is deemed a positive inj nry to the public prosperity. But, gentlemen, I found both kindness and justice. I found that above the prejudice which had been formal against us, there flowed a deep, broad stream of popular equality; that the hand of friendship was extended to tlio people of every nation, and that even Chinamen must live, be happy, successful, and respected in free America.' 1 gathered knowledge in your public schools; I learned to speak as you do; to read and write as you do ; to act and, think as you do; and, gentlemen, I rejoice that it is so ; that I have been able to cross this vast continent without the aid of an interpreter ; that here in the heart of the United States I can speak to you in your own familiar speech, and tell you how much, how very much, I appreciate your hospitality; how grateful I feel for the privileges and advantages I havu enjoyed in your glorious country; and how earnestly 1 inu that your example of enterprise, energy, vitality, and national generosity may be seen and understood, as I see and understand it, by our Government. Mr. Burlingame has dono much to promote good feeling in China toward the American nation. Ho made himself woll acquainted with the authorities at Pekin. He won their confidence to a remarkable degree. He is an excellent man, and, I believe, if his advice is received and acted upon, China will soon be the cordial friend of all the commercial powers of the earth. Already we are doing something in the way of progress in modern improvements. Steamboat lines have been established on our rivers, and the telegraph will soon connect us with the wonderful sovereignty of the Western hemisphere, where the people rule, where everything proclaims peace and good will to all. China must brush away the dust of her antiquity, and, looking across the Pacific, behold and profit by the new lessons of the New World. " We trust our visit, gentlemen, may be productive of gvod results to all of us ; that the two great countries, Eiurt and West, China and America, may be found forever together in friendship, and that a Chinaman in America, or an American in China, may find like protection and like consideration in their search for happiness and wealth." Tile Anthracite Coal Region. Concerning the anthracite coal region, which has been so much talked of in connection with the miners' strike, we find an interesting sketch in the Baltimore Sun. Its area is four hundred square miles, and one hundred and seven miles of it lie within the limits of Luzerne county, Pennsylvania. The total quantity raised in the whole State of Pennsylvania down to 1860, amounted to a little over eighty-threemillionsof tuns, of which Luzerne furnished twenty-nine millions. The first company for mining coal was formed in 1792, and it was five years before they shipped to Philadelphia, and this venture consisted of thirty tuns. The city authorities consented to take it, and tried to burn it under the boilers of the engines at the water-works, but it put the fire out. The balance was broken up and used in place of gravel over the sidewalks, and only the blacksmiths near the mines used the coal for home use. The discovery was made by n tavernkeeper, Jesse Fell, of Wilkesbarre, who concluded that a good draft was alone necessary to make it burn, and he built a grate of green hickory saplings, placed it in a large fireplace in his barroom, filled it with broken coal and dry wood under the grate and set it on fire ; the flames spreading through the coal, it was soon ignited, and before the wooden grate bars were consumed the success was proved, and hundreds of people flocked to the old tavern to witness the discovery.
This article was originally published with the title "A Siphon for Draining a Tunnel"