Q.-779. What takes place when the handle is placed in full release position? A.-Main reservoir pressure passes through a large, free opening at the end of the main slide valve into the train pipe. At the same time the pressure in the supplementary reservoir and chamber is discharged to the atmosphere. Main reservoir pressure also passes through ports E, into the governor cavity (Fig. 6), thence direct to the pump governor. Q.-780. Why is it necessary to discharge the pressure from the supplementary reservoir and chamber D in full release position? A.-In order to permit the train-pipe pressure in chamber A to force the piston to its normal position as shown in Fig. 4, where it must be at the commencement of the service application. Q.-781. What takes place when the brake valve is placed in running position, which is the next position on the quadrant? A. The large, free opening from the main reservoir to the train line is closed, and governor cavity E is connected direct to the train pipe by cavity M in the slide valve. Main reservoir pressure passes the excess pressure valve into governor cavity and train pipe. Air also passes from chamber A through cavity J and port H, charging the supplementary reservoir with train-pipe pressure. Q.-782. What is the purpose of the excess pressure valve? A.—To maintain in the main reservoir a predetermined pressure above that in the governor cavity and the train pipe. After this pressure has been attained in the main reservoir, the excess pressure valve will unseat, permitting pressure above the predetermined amount to pass into the governor cavity and the train pipe. Q.-783. What is excess pressure used for? A. For releasing brakes and recharging auxiliary reservoirs. (See Q. and A. 96-99.) Q.-784. What is the next position on the quadrant and what is it used for? A.-Lap. To blank all ports excepting that port between the train pipe and supplementary reservoir as previously explained. Q-785. What happens when the brake valve handle is placed in the next notch -the first of the service application notches? A.-Communication is shut off between the supplementary reservoir and train line; and the train-pipe exhaust port F in the main slide valve is moved past the edge of the graduating valve, permitting train-pipe pressure to pass into port F, and out through ports G and C to the atmosphere. This reduction of train-pipe pressure in chamber A, on the train-pipe side of the equalizing piston, allows the unchanged pressure in supplementary reservoir and chamber D to move the piston against the weaker train-line pressure, thereby through the medium of the fulcrumed lever, moving the graduating slide valve on the face of the main slide valve, and gradually closing the train-pipe exhaust port F. Q.-786. What happens if the brake valve handle is moved to any of the other service notches? A.-The same as explained in the preceding description, except that the further the handle is advanced, the further the train-line exhaust port F is moved away from the edge of the graduating slide valve, thus requiring a further advance of the equalizing piston to close the train-pipe exhaust port, which can only be brought about by a heavier reduction from the train pipe. Q.-787. How much pressure will be drawn from the train pipe if all the service notches have been used? A. From 23 to 25 pounds. Q.-788. What takes place when the handle is placed in the emergency posi tion? A.-Pressure is discharged direct from the train pipe through large ports J, K and C, to the atmosphere. Q.-789. What parts of the valve need lubrication? A. The main slide valve, graduating slide valve, equalizing piston and handle shaft, the usual lubricants being used. Q.-790. What is wrong if, when applying brakes on a train, or when brake valve is on lap, the governor stops the pump and prevents the accumulation of excess pressure with which to release and recharge brakes? A. A slight leakage past the excess pressure valve. In some cases this disorder is aggravated by the stopping up of the small pin hole in the pump gov ernor. Q.-791. How would you proceed to clean the excess pressure valve? A. After drawing off all the main reservoir pressure, remove the cap of the excess pressure valve, and rub clean with a little kerosene oil, replacing the parts dry. Q.-792. If, with a long train, and brake valve handle in full release position, train-pipe pressure increases very slowly, where should the trouble be looked for? ▸ A.-Lost motion on the inner end of the handle shaft, and in the links and pins between the handle and main slide valve. This lost motion decreases the opening past the main slide valve and stuck brakes may result. Q.-793. What provision has been made to assist the engineer in finding the running position when the sharp point of the handle latch has been worn off? A. A pin is set in on the inside face of the quadrant, just below the running notch, by feeling which with his finger the engineer may be guided to running position. Q.-794. What is wrong if the brake valve is handled properly and fails to automatically close off train-line exhaust, requiring the engineer to push the valve handle toward lap to stop the discharge from the train pipe? A. Any leakage of pressure from the supplementary reservoir or its connections. Q.-795. At what points may this leakage occur? A.-At any of the joints between the supplementary reservoir and brake valve, joint between cylinder head and valve body, but it is usually found in the packing leather of the equalizing piston. Q.-796. How can this leakage be located? A. If the leakage is to the atmosphere it may be found by coating the joint with soapsuds. If it is in the piston packing leather, after ascertaining that there is no leak in the slide valve move engineer's valve handle 53 to the running position to charge the supplementary reservoir, then let all air out of train line by moving handle to emergency position. If now the cut out cock in train pipe beneath engineer's valve be closed and the handle 53 placed in any service notch a leak by the packing leather from supplementary reservoir will be manifest by a movement of the black hand of the duplex gage. Q-796a.-Should a more exacting test be desired, how should it be made? A. By increasing train pipe volume, making it equivalent to the volume found with a long train. Then operate the valve to be tested, in service applications positions, to ascertain if the valve will automatically close off. If the train pipe discharge fails to totally close off, there is a leakage at some point from the equalizing reservoir cavity; probably past the packing leather of the equalizing piston. Q.-797. What could cause this leakage? A.-Packing leather improperly fitting the cylinder, being worn through by the expansion spring, or the bottom of the cylinder cut by dirt accumulating there from the train pipe. Q.-798. If the brake valve handle is left in full release position to quickly recharge a train, then moved direct from full release to first service notch, will the valve automatically close after the usual number of pounds has been drawn off? A.-No, because the supplementary reservoir was emptied in full release position, and the graduating feature of the valve depends on the train line and supple mentary reservoir pressures being equal at the commencement of the application. The handle was not stopped on running position to recharge the supplementary reservoir. Hence the graduating, equalizing feature of the valve is temporarily lost. Q.-799. Suppose a stop has been made with a fifteen pound reduction, and the brakes released in running position, to what position on the quadrant must the handle be moved to get a discharge of pressure from the train pipe? A.-No pressure will be discharged from the train pipe until the brake valve handle has been moved beyond the notch where the last application was made. The equalizing features of the preceding notches is rendered inoperative until after the supplementary reservoir has been emptied in full release position. Q.-800. How must this valve be handled to make it operate properly in applying brakes? A.-After each application the brake valve handle must be placed in full release position long enough to exhaust all air from the supplementary reservoir, left in running position long enough to recharge the supplementary reservoir from the train pipe, moved to the application notch representing the number of pounds to be drawn off, and left in that position until the exhaust is automatically closed. Q.-801. What will be the result if main slide valve leaks? A.-It usually releases brakes. Q.-802. How should leakage tests of the slide valve be made? A.-See Q. and A. 375. Q.-803. How should a stop be made with a high speed passenger train successfully on a slippery rail, i. e., when you cannot depend on sand as with a side wind or sand pipes stopped up? A.-Use the two application method; apply the brake hard with service application while speed is high; as the speed reduces to fifteen or eighteen miles per hour, release all brakes, and then apply the brake lightly for final stop. F. M. NELLIS, Committee.. Interesting Information. The Submarine and Land Telegraphs of the World. It presents some information regarding the submarine telegraphs of the world which is especially interesting at this time in view of the prospective construction of an all-American cable across the Pacific. It shows that the submarine telegraphs of the world number 1,750. Their aggregate length is nearly 200,000 miles; their total cost is estimated at $275,000,000, and the number of messages annually transmitted over them is more than 6,000,000. All the grand divisions of the earth are now connected by their wires, and from country to country and island to island the thoughts and words of mankind are instantaneously transmitted. Beneath all oceans save the Pacific the universal language which this system has created flows uninterruptedly, and man talks as face to face with his fellow man at the antipodes. Darkest Africa now converses daily with enlightened Europe or America, and the great events of the morning are known in the evening throughout the inhabited world. Adding to the submarine lines the land telegraph systems, by which they are connected and through which they bring interior points of various continents into instantaneous communication, the total length of telegraph lines of the world is 1,180,000 miles, the length of their single wires, or conductors, 3 800,000 miles, and the total number of messages annually sent over them about 400,000,000, or an average of more than 1,000,000 each day. In the short half century since the practicability of submarine telegraphy was demonstrated, the electric wires have invaded every ocean except the Pacific. Nearly a score of wires have been laid across the Atlantic, of which no less than thirteen now successfully operate between the United States and Europe, while three others span the comparatively short distance between South America and the African and south European coast lines. Throughout the Indian Ocean, lines connect the far east with Europe and America via the Red Sea, the Mediterranean, the western coast of Europe, and the great trans-Atlantic lines. The Mediterranean is crossed and recrossed in its entire length and breadth by numerous cable lines, and the "Mediterranean of America," the Gulf of Mexico and the Caribbean Sea, is traversed in all directions by lines which bring its islands and colonies into speaking relations with each other and with South America, Central America, the United States, and thence with Europe, Africa, Asia-the whole world. Along the eastern coast of Asia, cable lines loop from port to port, and island to island, receiving messages overland from eastern Europe via the Russia-Siberian land lines and forwarding them to Japan, China, Australia, New Zealand, the Straits Settlements, Hongkong and the Philippines, and receiving others in return. South America is skirted with cable lines along its entire border save the extreme south, where they are brought into intercommunication by land lines. Along the entire coast of Africa, cables loop from place to place, and from colony to colony, stretching along the entire circumference and penetrating the interior by land lines at various points. Every body of water lying between the inhabited portions of the earth, with the single exception of the Pacific Ocean, has been crossed and recrossed HEAD END COLLISION ON CHICAGO TERMINAL TRANSFER RAILWAY, BETWEEN BLUE ISLAND AND HARVEY by submarine telegraph lines. Even that vast expanse of water has been invaded along its margin, submarine wires stretching along its western border from Siberia to Australia, while its eastern borders are skirted with lines which stretch along the western coasts of the two Americas. Several adventurous pioneers in Pacific telegraphy have ventured to considerable distances and depths in that great ocean, one cable line running from Australia to New Zealand, a distance of over 1,000 miles, and another extending from Australia to the French colony of New Caledonia, 800 miles seaward. A cable which is to connect Canada with Australia across the Pacific is now being laid at the joint expense of the United Kingdom, Canada and the Australian Commonwealth, and has already been completed from Vancouver, British Columbia to Fanning Island, just south of the Hawaiian Islands, and it is expected that the entire line will be completed by the end of the present year. The chief obstacle in the past to the construction of a grand trans-Pacific cable was found in the fact that midocean resting places could not be satisfactorily obtained or arranged for, no single government controlling a sufficient number of suitable landing places to make this seem practicable, in view of the belief that the distance through which messages could be sent and cables controlled was limited. With landing places at Hawaii, Wake Island, Guam and the Philippines, however, no section of a cable stretching from the United States to Asia and touching at these points would have a length equal 'to that now in daily operation between France and the United States. The length of the French cable from Brest, France, to Cape Cod, Mass., is 3,250 miles, while the greatest distance from land to land on the proposed Pacific route would be that from San Francisco to Hawaii, 2,089 miles; that from Hawaii to Wake Island being 2,040 miles, from Wake Island to Guam 1,290 miles, from Guam to Manila 1,520 miles, and from Manila to the Asiatic coast 630 miles. While the depth of the Pacific is somewhat greater than that at which any cable has been laid, the difference between its depth and the greatest depth reached by cables in the Atlantic would be very slight, the cable recently laid from Haiti to the Windward Islands being in 18,000 feet of water. The recent survey for a cable between the Pacific coast and Manila justifies the belief that a route can be selected in which the depth will not exceed 20,000 feet, and may not exceed 18,000 feet. The recent survey made by the Bureau of Equipment, Navy Department, under the direction of Rear Admiral R. B. Bradford, disclosed the greatest ocean depths heretofore known lying between Midway Island and Guam and being 31,614 feet, or but 66 feet short of six miles depth of water. This depression, however, which has been named the "Nero Deep," in honor of the vessel from which the sounding was made, can be avoided by a detour. The Miner. LORNE E. GARTLEY. Deep down he toils and only sees the dawn His life is with grim Danger fraught and yet Let not oppression weigh him down: Give him |