An Automatic Mail Exchange System. FEW, if any, of the readers of this maga-* zine have failed to notice the crude apparatus in use at our small railway stations by which a single pouch of mail is deli vered to a flying train, but it is doubtful whether many realize that this mail exchange system has been the subject of more discussion among government off-cials, more study upon the part of inventors and the source of greater loss and annoyance to all concerned than almost any other piece of mechanism in the public service. Since 1869, when the first iron catcher arm was put into commission, practically no improvement has been made in the mail exchange system in use upon our railroads. Hardly had the mail catcher's arm of 1869 been put into commission than all connected with the service realized its ineff-ciency. Failure to collect or deliver the mail led to numberless petty quarrels between mail clerks and station employees. Frequently pouches thrown from passing trains or knocked from the cranes were sucked under the wheels of the cars and ground to powder. Worst of all, accidents to engine men and other employees who inadvertently put their heads out of the windows and were struck by the extending arms of the crane became so common that many inventers became interested in the subject. Plans by the hundred were suggested but few departed materially from the old design and all proved a failure when put to the test. Disappointed at their failure, the government retained the use of the former apparatus and accidents to employees and mail continued increasing rapidly as the service was extended. To-day there are more than 12,000 stations in this country where catcher service is in operation. This service is maintained at enormous expense because of the hand labor involved. Recently a western traveling man has developed a mail exchange system that is completely automatic. Either the compartment pattern or the full sized mail car, as now used in the railroad mail service, can be equipped with the new exchange system. The car equipment consists of a receiving arm or chute attached to the sides of the car door and folded when not in actual use, so that it extends but two inches from the side of the car. Running upon rollers in a false floor between the doors of the car is a steel delivery truck, capable of handling more than one thousand pounds of mail matter and arranged to dump its contents upon a special platform at an appointed spot along the track. The platform slants away from the track to prevent the pouches from piling up as they are deposited and a low railing surrounds it to overcome the possibility of the pouches rolling under the wheels of the train. The station equipment consists of from one to twelve steel station cranes as required, and one receiving platform as just described. Located at the side of the track, 44. feet from the receiving platform, is a trip which comes into contact with its counterpart upon the mail car as the train passes. A worm gear attached to the middIe of one of the axles of the mail car runs a driving shaft provided with a clutch. This clutch throws the mechanism into gear when one of the car trips attached to it comes in contact WIth th e trIP locat e d a1 ong the side of the trackway, as the car passes it. The mechanism makes one revo1 ution and then automatI. caIIy throws I. tse If out 0f gear. The first quarter of the revolution rings a gong in the car to notify the mail clerk that an exchange is to be made and opens the car door; the second quarter pushes out the delivery truck until it dumps the mail and opens the receiving chute; the third quarter holds the delivery truck in position while it dumps the mail and the receiving chute in position until the station cranes are passed and the mail upon them is conducted into the car; the fourth quarter pulls the delivery truck back into the car in the position it occupied before the mechanism was tripped, folds the receiving chute into its original position and closes t h e d oor 0 f t h e car. ThI' S comp I etes th e exchange and the device remains out of gear until again tripped at the next exchange station. Th e operatum 0 f th e mechamsm b emg reduced to an exact mathematical basis, or ratio, where, in a movement of one degree 0 f Its revol utI'On equa 1 s f our f eet 0 f traveI on the rails by the car wheels, the exchange must be positive. An adjustment is provided to take care of the different sizes of car wheels, wear, etc. Being geared to the axle, the mechanism runs fast, slow, forward or backward as the car runs, and if. for any reason, the car is stopped and backed up after passing the trip, and before the exchange is completed, the mechanism is turned backward with it. When started forward again it would bear the same relation to the car wheels as before. At terminals of the road the device can be quickly reversed and the receiving chutes changed to the opposite side of the door so that it I' S unnecessary to turn the mail car around for the return trip. The station equipment is limited to 12 cranes but instead of being obliged to use pouch es 0f a speCl. aI s"iape and S I' ze as WIth the present catcher system, pouches and tIe sac ks, 0f any W eI'ght f rom an em pty t o the h eav Ies t m t he ser VI' ce, may be use d and any class of mall handled m them. The delivery of mail is only limited by the number of mail cars in the train, as each car can delivor upon the platform the full capacity of its delivery truck, as required. All the former danger to engineer or passengers from being struck by the crane arms is eliminated in the new steel cranes which, when set for action, stand 30 inches from the side of the car. The extending arms of the crane are equipped with clamps for holding the pouches and are so protected that the pouches can be inserted into them in but one way, which insures the proper operation of the system. When relieved of their burden, the crane arms automatically swing to a parallel position with the track where they remain until set for the next exchange. For example, either part of the system may be made to work by itself so that if there is no collection to be made at a station the delivery of the mail only takes place, and vice versa. If no exchange whatever is to take place the mail clerk merely throws the mechanism out of gear with a lever. Human memory is sometimes tricky, however, and the mail clerk may forget to throw the mechanism out of gear before the station is reached. The gong rings and the device begins to operate. The mail clerk upon being reminded of his mistake, quickly throws the reversing lever and the mechanism runs backward and throws itself out of gear. Accommodations have also been made for the turning of the trucks on sharp curves by the use of knuckle and slip joints, so as not to interfere with the operation of the device, and the parts beneath the floor of the car are protected from injury by water, ice and snow or from flying stones and gravel of the roadbed. This mail exchange system has been tested hundreds of times at Overland Park, Kan., a suburb of Kansas City, in the past year. Exchanges averaging 450 pounds of mail on each trip have taken place at speeds varying from 5 to 40 miles an hour. Not one failure of the device has occurred nor a single damage to pouches or equipment thus far, and as a result of exhibitions of its operation, made in the presence of government officials, permISSIOn has been granted by the Post Office Department to | use the automatic exchange for handling I mail to test its practicability in the rogular service. It now remains for each individual road to relieve itself of the expense, delay and danger to its employees which are inherent qualities of the present mail exchange system. George Washington on Rumsey's Steamboat ONE of the earliest contests involving ^--'priority of an invention was the contest of James Rumsey to the claim of John Fitch to the steamboat invention and Mr. Rumsey had no less a witness in his behalf than George Washington, who, in an indorsement forming a part of the records of the case, says: "I have seen the model of Mr. Rumsey's boat, constructed to work against stream, examined the powerS upon which it acts, been eye-witness to an actual experiment in running water of some rapidity, and give it as my opinion (although I had little faith before) that he has discovered the art of working boats by mechanism and small manual assistance against rapid currents; that this discovery is of vast importance, may be of greatest usefulness in our inland navigation; and if it succeeds, of which I have no doubt, that the value of it is greatly enhanced by the simplicity of the works, which, when seen and expl ame d, may be executed by the most common mech anlC. ” GI' ven und er my h an d a t th e t own 0 f B a th , C ount y 0f B erk e1 ey, I. n th e s t a t e 0 f VIrglnla, thIS 7th 0 f S ept emb er, 1784 . "GEORGE WASHINGTON." Priest's Invention of a Fire Extinguisher INTERESTING accounts are received *from abroad concerning tests of a fre extinguisher understood to be the invention of a priest who has been decorated by November I I, J!Jl 1 SCIENTIFIC LEGAL NOTICES AMERICAN 436 PATENTS I you have an invention which you wish to patent you can write fully and freely to Munn&Co. for advice in regard to the best -way of obtaining protection. Please send sketches or a model of your invention and a description of the device, explaining its operation. All communications are strictly confidential. Our vast practice, extending over a period of more than sixty years, enables us in many cases to advise in regard to patentability -without any expense to the client. Our Hand Book on Patents is sent free on request. This explains our methods, terms, etc., in regard to PATENTS, TRADE MARKS, FOREIGN PATENTS, etc. All patents secured through us are described without cost to the patentee in the SCIENTIFIC AMERICAN. MUNN { COMPANY 361 BROADWAY, NEW YORK Branch Office, 625 F Street, Washington, D. C. A' I' E N “T* S SECUflu OrD FEE ' IJI' I J RRT1IRNR1 PA T t, ii T S Uf uuRNrD Free re port as to Pa tentability. Illustrated Guide Book. and What '0 Invent witl Lilt of Inventions Wanted and Prizes offered for inveltions sent free. VICTOR J. FV AN”&(0 .• Washington. T).C. Classified Advertisements Advertising I this column i. 7;) cents a line. No less tball four nor more t nan 12 Jines acce m ed. Count seven words to the line. All orders must be accompanied by a remit! ance. BUSINESS OPPORTUNITIES. TO INVENTORS—Large manufacturinf concern with a traineI sel1;ng fo;ce c3vering the whole country will manut aeture and marKet on a royalty basis an.v article that call be sold by sample at n large profit and for which a large demand can be crEau·d. Address with full delcrlptlOn : Machinery. P. o. Box 5;-39. Boston. Mass. A BERfIN P A TENT ATTORNEY desires to enter into negotmt i on s with a competent and ·b s olutely reliable young representative resinent in Washington, with a view to mutual co-operation in patent cases. Offers, with references, to be addressed to “ Berlin Patent Attorney,” care of this journal. FOR SALE. LOCAL REPRESENT AL'1 VE W ANTED.-Splenrid income assured right man to act as our representative afler learmng our businels thoroughly by mai!o Former exp eripnce un necessary. All we require is honesty , ability, ambition and wUling negs to learn a l ucrative busii-ness. No soliCiting or rraveling. rphis is an exceptional opportunity for a man in your section to get into a big paying business wHhout capital and become independ· ent for lite. Write at once for full particulars. Ad-tlres8 E. R. Marden, Pres .• The National Co-Operative Heal Estate Company, L 378 Mardeu Building. Washington, D. C. PATENTS FOR SALE. FOR S ALE- Pat. No. 1,005,567, Bed Bug Trap, neat. clean aud easy way of forever ridding a bore of bed bugs at small expense, nothing on the market like it, will be a sure winner W. H. McDonald, Pima, Arizona. STRAIGHT OFFFR.-For sale. U. S. Pat. No. 99 ·.09, and Canadian Pat. No. 129,415 for a New Cbain Grate (travelling Br'te) ;itn autoHtic dral: egulation. Increas!d efficiency. A ddress H. Flotssel, Kiel, Ger:any: MALE HELP WANTED. WANTED.- PAY OR BOARD AT S'lART TO learn trades, Automobiles, Electricity, Bricklaying, Plumbing. by actual work on lobs. Only few months reqUIred. No apprentICeshIp drudgery. 200 students last year. Catalogue free. United 'rade School, Dept. H, lJos Angeles, Cal. TYPEWRITERS. CLEARANCE SALE-RemILgtons, Densmores, Manhattans. Jewetts, $11.60 ea., Franklins. Hammonds, $gea. “ argains in Underwoods. Smiths, others; all glaranteed. Standard 'lyvewnter Exchange, 23 Park Row. N. Y. WANTED. ,v ANTED.-One second-class laboratorian at $3.52 per diem. A competitive examination wll1 be held November 27.1911, at the Navy Yard, Wasbingron. D.C., for filling the above pOSition. J"''or fUrther mformation address “Commandant, Navy Yard, Washington, D.C.'' MISCELLANEOUS. fhemicaJ Analyses, Assay, Microscopical tests. etc. InvestlgatJons and advice in a!l chemical questions. 2·2 years experience. Parobek Chemical - Laboratory, 362 South Broad Street, Trenton, New Jersey. F.EI TUI'ION BY MAIL.-CiviL 8ervicp, Drawing. Engineerillg, ElectriC Wiring, Agricultural. Poultry. Normal. Academic, Bookkeeping, Shorthand Courses. Matriculation $5. T\ free to first l¥ p gcants. A ppl;t[b c AiGIE COLLEGE, RJGE), OHr6. FRL !l^'-INVES'ING .OR PlOFIT” Magazine. Send me your name and l will mail you thls magazine absolutely free. Before you invest a doJlar anywhere-get this magmzine -it is worth $10 a copy to any man who Illtends to invest *5 or more per month. ''ells you how $1.0011 c,m grow to $22.10 -how to judge different cJasses of inve"UDents ; the Heal I!iarning Power of your money. This maga zine six mont h s treo if you write to-day. I. L. Harber, Publisher, 423, 28 W. Jackson Blvd .• Chicago. INQUIRY COLUMN Inquh-y “ m . 92;'.-\anted, to buy a patent roller, a ball-bearing axle. which could be purcba:ed on a royalty basis; it must be cheap and ful1y proved. inquiry No. 9*2.: H . Wanted addresses of parties baving Pitchblende deposits. if able to ship ore. In(Juiry No. 9*2a1. Wanted addresses of firms sel l ing second-hand water turbine s. Inquiry No. HZ;8.—vYanted addresses of parties having gem materials to offer in any part of the world. Inquiry No. 925!J.-\anted to buy a machine for removing the co!)ng of a filbert. tnquiry No. 9260.—Want addresses of parties able ao ship cnrundur, garnet. flint, emery or any material Suitable as an aurasive. the French Government. In describing the invention in a report published by the Bureau of Manufactures, Consul-General Griffiths of London, says: "Two cylinders are used, one of which is small and charged with 'ignifuge' gases which by connecting tubes are used to expel the solution from a much larger cylinder through an ordinary nozzle. The compound is described as follows: "1. A mixture of ignifuge gases, which, as a physical agent, utilizes its elastic force to project a liquid impregnated with salts and as a chemical agent renders the gases of the atmosphere which burn in every fire incombustible. "2. An effervescent liquid, in which are found salts in a state of solution. These salts, unknown before, were obtained by the Abbe D. Daney through electric furnaces of 3,000 to 5,000 amperes. When projected they produce other extinguishing gases which inerease the effect of the ignifuge gases referred to above. When reaching the blazing material they cover it with a peculiar dustlike coat, which makes it fireprQof." Notes for Inventors False Prophets. - In the face of the enormous increase in the issue of patents from year to year, it is recalled that forty years or more ago an examiner in the division of agricultural implements of the Patent Office announced dogmatically that plows had been perfected and that no more patents would be granted for plows. About the same time an attorney engaged in soliciting patents declared his intention of going out of the business since about everything had been patented that could be. A Laminated Rail-joint.-In a patent (No. 1,005,146) John A. Bodkin of New York city shows a splice bar forming the fsh plate of a rail-joint and composed of a series of long, thin plates lying side by side and increasing gradually in width throughout the series so that their edges may coincide with one another and also with the outer edges of the base and ball of the rail. Another Safety Device for Aeronauts.-A safety device, patented (No. 1,005,569) by Auld Weinberg De Meir of Providence, R. 1., takes the form of a garment whose body portion is provided with exterior air chambers. The air chambers are arranged in superposed rows extending around the garment and open at the bottom and have a vent at the top and are adapted to perform the function of a parachute. A Reversible Glove.-A reversible glove, which has oppositely disposed inserts, Ole of which forms the back of one finger and the other the front of another finger, is shown in patent (No. 1,005,437) granted to Charles H. Leavengood of Coshocton, Ohio, assignor of one-half to John A. Hesket of the same place. A Dressing for Felt Hats. - Large fortunes have been made out of dressings and polishes for men's shoes. The men who wear shoes also wear hats, and these are oftener discarded because they lose their color than because of wear. Will not some one invent a dressing, it may be in the form of a dye, easily applied to a hat, and serving to freshen it up and improve its appearance ? Possibly the dressing would have to be applied in some original way, but this can, doubtless, be devised by one experienced in the manipulation of felts, and it should be of such a character as to be easily and effectually handled by the ordinary wearer. A Safety Apparatus for Mines. - The mine safety apparatus, provided in patent No. 1,005,196, to Maturen Gold of Hay-ward, Okla., and William A. Montgomery of Loland, N. M., provides a system of pipes in a mine and provided at intervals with taps, a blower for forcing air through the pipes and a helmet with an air vent and with air inlet pipes with couplings which may be connected with the taps of the main pipes. The apparatus also includes a water pipe provided with mean, for distributing water at different points within the mine. in->ints The Goodyear Ideal of a Winter Tire No-Rim-Cut-10% Oversize-With a Tough, Deep- Cut, Dou6le- Thick, Nn-Skid Tread The Most Popular Tire Goodyear No-Rim-Cut tires have suddenly come into dominant place in America. The sale has thrice doubled in the past two years. Our last month's record shows a gain over last year of 343 per cent. No-Rim-Cut tires are now outselling any other type of tire. Over 700,000 have been used to date. And for next year's demand we have increased our capacity to 3,800 per day. Saving Half The reasons are theee: These patented tires make rim-cutting impossible. Not an instance of rim-cutting has ever occurred in the 700,000 iold. With the old type tire-the clincher tire - statistics show that 23 per cent. of all ruined tires are rim-cut. This worry and expense is ended forever with users of Goodyear No-Rim-Cut tires. Then No-Rim-Cut tires are 10% over the rated size. That means 10% more air - 10% greater carrying capacity. And that, with the average car, adds 25% to the tire mileage. This extra size takes care of the extras added to a car. It avoids the blowouts due to overloading. These two features together -No-Rim-Cut and oversize-under average conditions cut tire b1s in two. That has been proved ,ens of thousandH of times. Yet No-Rim-Cut tires now cost no more than other standard tires. That is why this tire-our patented type-has become the leading tire of America. The Thousand-Grip Tread Now thesc tires, if you wish, come fitted with an ideal Non-Skid tread. Not flimsy proj ections cut in the regular tread. Not metal and rubber, which never combine. This is an extra tread, made of very tough rubber, vulcanized onto our regular tread. Thus it gives you a double-thick tread. The extra tread is immensely wear-resisting. It is so thick that the blocks can be cut very deep. It is almost proof against puncture. The deep-cut blocks grasp the r 0 a d surface with countless edges and angles. Each block widens out at the base, so that the strain is distributed just as widely as it is with a smooth-tread tire. There has never been invented a device against skidding which compares with this Non-Skid tread. Note its thickness. Note its edges and angles. Judge for yourself its irresistible grip. In wet and wintry weather safety requires this tire. Our Tire Book, based on 12 years of tire making, is filled with facts you should know. Ask us to mail it to you. The Goodyear Tire&Rubber Co. First Street, - Aron, Ohio Branches and Agencies in 103 Principal Cities We Make All Kinds of Rubber Tires, Tire Accessories and Repair Outfits Main Canadian Office, Toronto, Onto Canadian Factory, Bowmanville, Onto (422) 436 SCIENTIFIC AMERICAN November 11. 1911 Supplements Hammer and Nails You can't nail down everything-some pieces of wood you can't drive a greased nail through without splitting them.There's where you need a tube or bottle of UFR AGE'S Has a holding strength per sq. inch equal to that of three six-penny nails driven 1J£ inches into solid oak. Applied direct from tube or with metal spreader from our solid cap bottles. Always ready for use, for it absolutely can't dry out unless you leave the cover off. Get a tube or bottle today and write for free booklet. .. Glue-ism.” which gives 101 useful ways to use this neat. quick. strong adhesive. FREE SAMPLE Goes With First Letter Something new. Every firm wants it. Orders $1.00 to $100. Big demand everywhere. Nice pleasant business. Write at once. METALLIC SIGN CO., 438 N. Clark, Chicaco GaVERSTICI JL. _ g they i-vfiM-i-T iv I LV n.: protection « needed, tkfl m ;- •. • L* of the shut. f EVERYBODY NEEDS EVERSTICKS. Always for saJB where ga<Kl slioeafiTO sold, I ACCEPT NO SUBSTITUTES. I THE OKI TfllS cord. THE ADAMS 8 FORD CO. CLEVELAND, 0. The celebrated Jaeger r Underwear is suitable alike [for men, women and children, and for all conditions |of health and occupation. t Recommended by the Medical Profession everywhere. Explanator) catalogue and samples free on request. Dr. Jaeger'8 !. w. s. Co.'s Own Stores New York: 306 Fifth Avenne, 22 Maiden Lane. Brooklyn: 504 Fulton St. Bo.ton: 228 Boylston St. Philadelphia: 1516 Chestnut St. Chicago: 126 N. State St Agents in all Principal Cities.