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stoves of the Siemens-Cowper-Cochrane type, 18 feet in diameter and 60 feet high. The Aux, as well as the ore and fuel, is hoisted and fed to the mouth of the furnace in successive layers, the flux being limestone, the fuel coke and anthracite coal, and the ores hematites and magnetites.

The stock yard for the open hearth furnaces is served by three electric traveling cranes of 20 tons' and 60 tons' capacity. The materials are received on elevated railroad tracks, and piled preparatory to sending to the furnaces. There are ii open hearth furnaces of 10 tons,' 20 tons', and 40 tons' capacity, with Siemens gas producers. Iron

from 25 to 75 tons' capacity. Some of the nickel-steel armor-plate ingots weigh as much as 122 gross tons, although the plate when finished with portholes cut out weighs only 27.6 gross tons.

After being heated, the armor-plate ingot is forged to the required dimensions by a forging press having a capacity of 14,000 tons, this press being served by combination hydraulic-pneumatic cranes of 200 tons' capacity, having a hydraulic lift and pneumatic travel. Exclusive of counterweights used, the Porter bar and chuck which holds the plate for forging weighs nearly 65 tons.

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BETALLEEN STEEL GE

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boxes are used for delivering the stock to the charging floor. These boxes are loaded on narrow-gauge carriages; and electric charging machines, together with a 25-ton electric crane, are used in charging the furnaces.

To handle the molten metal, immense ladles are provided, which run on tracks, the molten metal being packed into these ladles and from them into the moulds of the size required for casting the steel armor-plate ingots. These ingots are allowed to cool in the moulds for one or two days. Their removal from the moulds is accomplished by the aid of several electric and pneumatic cranes of

After the armor-plate has been rough· forged to size and reheated, it is sent to the bending press to be straightened or bent to shape. In the case of a conning tower, for example, the carbonized plates are bent to a circle having a radius of 38 inches. The bending press exerts a hydraulic thrust of 7,000 tons, and has two independently operated plungers. This press is served by two hydraulic cranes of 75 tons' capacity, and by directfired furnaces with movable car bottoms.

The armor-plate machine shop at the Bethlehem steel plant is equipped with very large machine tools and the latest labor-saving devices. In this shop the various groups of plates, before being

406

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LADLES AT OPEN HEARTH FURNACES.

plates weighing 406 tons. These plates are 17 inches thick, the size of the barbette being 12 feet 1 inch by 34 feet 7 inches. The nickelsteel plates for the side armor of the Russian battleship Petropavlovsk were made to taper in thickness from 16 inches to 8 inches, and were 7 feet 8 inches high, the weight of the plates shown in the accompanying illustration being somewhat over 140 tons.

Armor-plate manufactured at the present time receives

very severe tests, as may be seen from the accompanying photographs. A nickel-steel oil-tempered ballistic plate was tested with three shots from an 8-inch gun, the projectile weighing 250 lbs. and having a velocity of 1,400 foot-seconds, the energy being 3,400 foot-tons. The penetration was 10/2 inches and II inches, the plate being slightly bulged. The size of this plate was 136 inches by 91 inches.

The Kruppized steel ballistic plate seen in the accompanying illustration was also tested with three shots, a 12-inch gun being used. This plate was 1511/2 inches long by 97 inches wide and 12 inches

shipped, are assembled for final inspection, in the positions they will occupy on the vessel. The accompanying illustration shows loaded on the shorter of the two trains, the Harveyized armor-plates for the turret of the U. S. battleship Al abama, which weighed 166 tons, the thickness of the plates being 14 inches ; also, loaded on the longer train, 34 side armor-plates for the Russian battleship Retvizan, this Krupp armor being 9 inches thick and weighing 500 tons. The barbette for a 13-inch gun turret on the U. S. battleship Indiana, constructed at the Bethlehem plant, consisted of 13

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Inventions

The Problem of Getting a Patent-The Requisite Steps—Pitfalls to be

Avoided-Qualifications of the Solicitor

Second Paper

By EVERETT E, KENT
Counselor-at-Law and Patent Attorney

INERVA, deity and good genius of the Greeks, stepped forth from the brain of Jove, mature

and fully armed at birth. Modern brains work with less facility. The record thus established by Jove is rarely equaled to-day. The usual history of a commercially successful invention is a record of experiments and partial successes, involving adjustment and readjustment and new devices before the idea is complete and the machine in conclition to work smoothly and compete effectively in the market.

This means expenditure of time, money, and labor by the inventor. Conversely, it furnishes to a host of other thoughtful minds—to every one who learns it, in fact-opportunity to invent and patent improvements upon the original device. A broad-minded owner of the original invention will always give respectful consideration to such improvements with a view to their purchase. Many a business may thus be made secure, though based on a main patent which is weak and tottering; and so, likewise, a monopoly may be extended after the expiration of the main patent. This happens when the control of the subsidiary invention, no matter how small it may be, enables its owner to present to purchasers a more attractive proposition than competitors who are free to sell or use only the original device are able to offer. Notable instances of this are the telephone monopoly and the two great electrical machinery companies, whose fundamental patents have already

expired, but who continue, nevertheless, to dominate the market.

A Wise Precaution Before much expenditure, it is well to learn what progress others have already made in the art to which the invention relates. This is most conveniently done by an examination at Washington of the records of patents previously granted, supplemented, perhaps, by a glance into a suitable mechanical dictionary or textbook. A cursory search costing but a few dollars enables the inventor to judge whether it is worth while to continue his experiments and to go to the expense of an application for patent. The best way is to send to a patent attorney a simple sketch and description of the invention sufficient to convey the idea, stating what is thought to be novel. This is cheaper and more effective than for the inventor to attempt the search himself. The Patent Office will not make such a search except in connection with an actual application for patent. The annual indexes of patents, which can be found in public libraries throughout the country, are not classified with sufficient analytical exactness to be used with satisfactory results for this purpose.

The preliminary search may show that a crude form of the device has already been conceived by another. The inventor must then consider whether his improvement is a sufficient advance to amount to a patentable invention; and whether such a patent, being narrower than first expected, would be worth its cost. The

fact that the earlier patent may still be sign the invention, and his rights to a in force and may contain claims dominat- patent thereon. Sometimes an ining his idea, will not prevent the grant vention is made in the course of of a patent to him upon his specific im- a man's employment, as a part of the provement; but he will not thereby ac duties for which he receives a salary. In quire any right or license to use the sub- such cases the invention is sold in adject-matter of the earlier patent. Each vance. If the inventor refuses to execute patent stands on its own merits, and re- proper application papers and an assignmains unaffected by subsequent patents. ment to his employer, he may be comThe improvement may be useful enough pelled to do so by an order of court. The to justify hope of an amicable arrange- mere fact, however, that a man is an ment with the earlier patentee, either by employee, does not entitle his employer purchase or sale, or by exchange of to the patent, if the making of the inlicenses, so that both patents will be vention be outside the scope of his duties. worked together. In cases of doubt, especially where the

Choosing a Solicitor validity of an issued patent is questioned,

The most important single feature cona more exhaustive search to show the

nected with procuring the patent, is the state of the art can be made at an ex

selection of the solicitor who is to manpense running from $20 to $100 or more,

age the application. Upon his ability according to the time consumed by the

and integrity, more than on anything else, expert in making the search.

depend the scope and value of the patent. The Formal Application

The art of soliciting patents is highly

technical. There are men of all grades A formal application for a patent in of ability in this profession, as in others; the United States consists of a specifica- and unfortunately there are some quacks tion, claims, oath, and petition; also a —men who could be called impostors but drawing where the nature of the case ad- for the fact that their names are in truth mits of it. A model is but rarely re- officially registered as attorneys. Inasquired. With a certain grim humor, much as inventors and men of genius are however, the Patent Office invariably re- notably poor business men, a word of quires a working model when the inven- warning here can do no harm. Just as tion is a perpetual motion machine. The every business concern which advertises government filing fee is $15. The speci- to sell something for nothing proves to fication must describe the invention be a fraud, so a person who offers to clearly, and the manner of making and solicit patents at rates less than ordinary, using it; also, if it be a machine, it must and sometimes to give a bonus in addiexplain its principle, and the best mode tion, will generally give services that are in which the inventor has contemplated in some way worth correspondingly less. applying that principle. It is a fraud on Do not let your judgment be warped by the public, and the patent may be de- a lean pocketbook. Some kinds of clared invalid, if the inventor withholds "economy” come high. If the invention the best mode he knows.

is valuable, if you hope to sell it for one The person who signs the application thousand or one hundred thousand dolhas to make oath that he believes himself lars or more, the difference of a few to be the original and first inventor of the dollars paid to employ a competent soimprovement; and that he does not know, licitor may make the difference of hunand does not believe, that the same was dreds or thousands of dollars in the sellever known or used before his invention ing price. It is not impossible that it or discovery thereof. This provision of may make the difference between a patlaw prevents the issue of a valid patentent that is salable and one that cannot on the application of any person who be sold at any price. The unfortunate first learned of the invention from an- thing is that no inventor, unless he be other, whether honestly — in a friendly himself an expert, is able to judge how way, or by agreement or purchase—or well his case is being handled—not even dishonestly, by theft.

on receiving and examining the patent. The original inventor may sell or as- The quality of it does not appear until

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