Sivut kuvina
PDF
ePub

REAR-ADMIRAL N. C. TWINING, U. S. Navy.-The attention of the Bureau of Ordnance, Navy Department, has been drawn to a statement made by Dr. Charles E. Munroe in a paper read before the Interantional Congress of Applied Chemists, in London, 1909, to the effect that provision had been made to rework U. S. navy smokeless powder every three years. This statement has tended to create an erroneous impression, particularly abroad, and to cast an exaggerated and unwarranted suspicion on American powder, which it is desired to correct.

To understand the situation clearly, it is necessary to state that smokeless powder for the U. S. army and navy is made under government specifications prepared by a Joint Board of Arm and Navy Officers from results obtained after years of experimentation and exhaustive tests by ordnance and chemical experts. Every effort has been made to improve the process of manufacture and the bureau can state positively that the powder as now manufactured will, under normal conditions of storage, enjoy a life of from twelve to fifteen years, and possibly longer.

The bureau now has powder in service which is from seven to twelve years old and which is still in excellent condition as to stability; this powder was manufactured before certain improvements in the process of manufacture now in vogue were adopted; these improvements render certain a longer life of powder into the manufacture of which they have been introduced.

The bureau has established a reworking plant for the purpose of reworking such powder as may prove unsatisfactory; by the use of this process powder which it is necessary to condemn for any reason can be made over into new powder of the best quality at a small cost instead of being a total loss.

At about the time Dr. Munroe was preparing the paper above mentioned the bureau made marked improvements in the process of manufacture of smokeless powder by the introduction of a stabilizer. This has been acknowledged by Dr. Munroe as will be seen from the following copy of his letter on October 6, 1911, to Mr. H. F. Brown of the Du Pont Powder Company, which is published by the kind permission of Mr. Brown and Dr. Munroe:

EIGHTH INTERNATIONAL CONGRESS OF APPLIED CHEMISTRY, WASHINGTON AND NEW YORK, SEPTEMBER, 1912.

October 6, 1911.

Mr. H. F. Brown, Director Smokeless Powder Department, E. I. Du Pont de Nemours Powder Company., Wilmington, Del,

DEAR SIR: Replying to your inquiry regarding the statement made in my London paper in 1900, viz. "To insure stability, provision is made for reworking the powder every three years I state that such frequent reworking of the powder has not been found necessary even with the older form of powder and that moreover, while my paper was being published, such improvements were made in the manufacture and stabilization of the U. S. powder referred to as to greatly improve its keeping qualities. The experience of the users of this powder and the results of the tests made indicate that the powder as it is now and has been made for some years will enjoy a life of from twelve to fifteen years and probably longer.

Yours very truly,

(Sd.) CHARLES E. MUNROE.

THE HYDRO-AEROPLANE FOR THE NAVY.-The success of Lieuts. T. Gordon Ellyson and John G. Towers in flying in a hydro-aeroplane down Chesapeake Bay from Annapolis to Buckroe Beach, Va., a distance of 145 miles, in 147 minutes, will justify Secretary Meyer in asking Congress in December for a liberal appropriation to equip the navy with airships of the amphibious class.

When the Secretary wrote his report a year ago, Mr. Eugene Ely had recently (on November 14) made a flight in a Curtiss biplane from a temporary platform on the forward deck of the scout cruiser Birmingham, and Mr. Meyer said in his report.

"The Department contemplates further experiments along these lines. with the belief that it will be necessary in the near future to equip all scouts with one or more aeroplanes to increase the distance at which information can be secured."

A hydro-aeroplane is an aeroplane fitted with attachments to facilitate the starting of the airship from the surface of water and its alighting on the same element. A Frenchman, M. Henri Fabre, was the pioneer of amphibious locomotion, making the first flight at Martinique on March 20, 1910. Mr. Glenn Curtiss had begun to experiment on Lake Keuka the previous year, but it was not until January 26-27, 1911, that in San Diego Bay he rose from the water, and after taking his course through the air settled down again on the surface of the bay with the ease of a gull. His hydro-aeroplane developed a speed of forty-five miles an hour on top of the water, and in the air it traveled fifty miles an hour.

On February 27 Mr. Curtiss flew from North Island to the side of the cruiser Pennsylvania, and the airship was drawn up from the water and placed on the forward deck, as if it were an auxiliary for scouting purposes. A week later Lieut. T. Gordon Ellyson was taken up with the aviator for a flight of one and a half miles at a speed varying from twentyfive to fifty miles an hour, Lieutenant Ellyson sitting on the pontoon rigged below the aviator's seat. From this position Lieutenant Ellyson could see bottom at a depth of twenty-five feet, and he afterward said that in clear water it would be possible to see from the hydro-aeroplane a submarine traveling under the surface. It was also the lieutenant's opinion that when the airship was moving at the comparatively slow speed of twenty-five miles an hour bombs could be dropped with precision from the pontoon.

Mr. Curtiss began his experiments at San Diego by attaching to his lower plane, at about the center, a float six by five feet and one foot thick. arranged at an angle of ten or twelve degrees. In front of this, about the place of the wheel in a land machine, he attached another float six feet wide, one foot from front to rear and six inches in depth, and ahead of that float he fixed a small elevating hydro-plane. He found the combination too cumbrous and substituted a single float twelve feet long by two wide with a depth of twelve inches, resembling a scow, curved upward at the bow and downward at the stern. The weight was only fifty pounds. Thus equipped the aeroplane ran over the surface of the water with hardly any disturbance and rose into the air quickly and smoothly.

As Lieutenant Ellyson became Mr. Curtiss's pupil the presumption is that the hydro-aeroplane used on Chesapeake Bay had the equipment which we have described. In one account of this remarkable flight by two men on land and water, which has never been equalled, it is said that near Buckroe Beach “the engine was stopped and the big hydro-aeroplane was allowed to settle on the water," and that then the gear was changed to the propeller shaft and the machine was run ashore." Apparently enough speed was attained to drive her up on the sands. It is to be noted that a strong east wind prevailed during the trip along the west shore of Chesapeake Bay, and that the machine was sometimes flying seventy miles an hour.

It is obvious that the hydro-aeroplane could not take to the water when any kind of a sea was running. In the present stage of development it is a craft for use on inland waters or on bays when the surface water is not rough. Nevertheless, the value of the hydro-aeroplane as an auxiliary to naval vessels for reconnoissance and for conveying despatches, and for light transportation both in peace and war, cannot be seriously disputed. Its employment for damaging or destroying an enemy's ship with explosives may still be debatable.-New York Sun.

BOOK NOTICES.

"Submarines of the World's Navies." By Charles W. Domville-Fife. Published by J. B. Lippincott Company, Washington Square, Philadelphia, Pennsylvania.

The author ably outlines in his preface to this attractive, well illustrated and well arranged book, the field he endeavors to cover; he says "In the description of the submarine torpedo boats of the various naval powers, it has been the object to point out the differences of the vessels, types and clases; with the purpose of showing their fighting value and efficiency. and of giving an idea of their construction, without occupying undue space, or wearying the non-technical mind with the description of details which are common, in one form or another, to every submarine boat."

This book has the fault, an unavoidable one in any publication descrip tive of so rapidly developing and changing a subject, of being some months behind the newest developments, and consequently is of little value to the naval expert. Its information, however, seems to be accurate up to about the last of the year 1909, and will enable the lay reader to obtain a good comparative idea of the attitude of the world's navies toward this newest type of craft, and of their progress in its development.

The brief communications in Part III, from some of the world's authori ties on the subject, give the reader a correct impression of the true value and possibilities and also of the limitations and dangers, of this type of craft as seen by their designers and commanders.

The book is well written and extremely readable, and will doubtless prove itself interesting to a large section of the American public, as it treats of an up-to-date subject about which comparatively little has been published, and which has been surrounded with an air of mystery which is, unfortunately, not wholly dispelled by the present writer.

R. H. DANFORTH.

"Studies, Military and Diplomatic, 1775-1865." By Charles Francis Adams: The Macmillan Company. Contents. Military Studies. The Battle of Bunker Hill. Battle of Long Island. Washington and Cavalry. The Revolutionary Campaign of 1777. The Battle of New Orleans. The Ethics of Secession. Some Phases of the Civil War. Lee's Centennial. Diplomatic Studies. An Historical Residuum. Queen Victoria and the

Civil War.

A splendid work. The author is evidently on familiar ground, and the completed volume shows both familiarity with and careful study of the subjects under consideration. Facts and deductions there from are presented in a pleasing and delightful manner. The illustrative battles and military subjects are happily selected, making a book that must be of interest to the American people. To the military student this work will be of inestimable value and fulfils a long felt want.

The Diplomatic Studies must be of great interest to all patriotic Americans, dealing as they do with the greatest crisis in the history of our great

republic. The book is pleasing and instructive, and after careful reading one regrets that there is not more.-Price, $2.50 net.

D. W. WURtsbaugh.

"A Handbook of Wireless Telegraphy." J. Erskine Murray, D. Sc. (third edition, 1911): D. Van Nostrand Co.; $3.50.

This book is written in a popular, and, for the most part, non-mathe matical style, and will prove exceedingly interesting to those who have some slight knowledge of wireless telegraphy. In addition it will be of use as a work of reference to the specialist inasmuch as the author has gathered together accounts of many types of comparatively little known apparatus and many interesting experiments which, up to the present time, have been described only in scattered articles in the technical journals. In the descriptions of the different so-called systems the author has quite naturally taken the statements of the manufacturers for the attainments of their systems. These, of course, will be taken with a grain of salt. In such cases the distances given as having been covered by the appartus are usually made at night which, as is now known, gives no criterion of the excellence of the apparatus. The book contains a brief history of the development of wireless telegraphy, including the early attempts at signaling without wires, which led up to wireless telegraphy itself. A brief account is given of various systems, the lesser known being described almost as completely as those which have a wider use. A curious omission in this particular is the failure to describe the present Telefunken quenched spark apparatus. Among the interesting experiments described are those of Duddell and Taylor with the steamer "Monarch" on the variation of received current with the distance. Attention is also given to the experiments of Captain Wildman in Alaska on the measurements of received current. These were among the first attempts to apply quantitative methods to wireless telegraphic transmission.

The following list of the chapter headings will give a good idea of the material covered in the book: I, Adaptations of the Electric Current to Telegraphy; II, Earlier Attempts at Wireless Telegraphy; III, Apparatus Used in the Production of High Frequency Currents; IV, Detection of Short-lived Currents of High Frequency by Means of Imperfect Electrical Contacts; V, Detection of Oscillatory Currents of High Frequency by Their Effects on Magnetized Iron; VI, Thermometric Detectors of Oscillatory Currents of High Frequency; VII, Electrolytic Detectors and Crystalline Rectifiers; VIII, The Marconi System; IX, The Lodge-Muirhead System; X, The Fessenden System; XI, The Hozier-Brown System; XII, Wireless Telegraphy in Alaska; XIII, The De Forest System-the Poulsen System-the Telefunken System; XIV, The Lepel and Other Shock-excitation Systems; XV, Directed Systems; XVI, Some Points in the Theory of Jigs and Jiggers; XVII, On Theories of Transmission; XVIII, Worldwave Telegraphy; XIX, Adjustments, Electrical Measurements, and Fault Testing; XX, On the Calculations of a Syntonic Wireless Telegraph Station; XXI, Tables and Notes; Appendix, Radiotelegraph Convention Service Instructions.

L. W. AUSTIN.

66

'Internal Combustion Engine Manual." By F. W. Sterling, Lieutenant, U. S. N., School of Marine Engineering, U. S. Naval Academy.

A treatise on internal combustion Engines written primarily as a text book for midshipmen. The time allowed for this course is limited to about twelve lessons, hence the subject is very briefly treated.

In the foreword the author gives the following information:

"(a) The subject of fuels is first treated fully, this being the fundamental element that governs design and operation. These fuels follow in a natural sequence which order is preserved when carburetion is taken up in Chapter V.

"(b) The engine proper naturally divides itself into four systems: (1) fuel system, (2) ignition system, (3) cooling system, (4) lubrication system. These are treated in detail in the above order and in Chapter X the four systems assembled are illustrated by modern commercial engines.

[ocr errors]

(c) Producer plants being closely allied to gas engines are given a short chapter at the end of the book."

2. The author describes the details of construction of the various parts of the engine in Chapter III, and in the next chapter explains the principles of action of the two- and four-cycle types. A more logical arrangement would be made if these subjects were treated in the reverse order.

In the early part of the text the heat balance of an internal combustion engine, and of a steam engine plant are very cleverly diagrammatically compared, and these two forms of motive power are generally compared. This should come later in the book, perhaps in the chapter that treats of the thermal efficiency of the engine.

With the above exception, the book is logically arranged, and more meat is given than in many other books of much larger size.

3. In the chapter on fuel systems only one of each type of caburetor is described. These are well selected, showing the difference in design required by the different fuels; and embody the principles of all carburetors The sketches of electric spark ignition being diagrammatic are very easily understood.

In the chapter on faults, the usual defects and their remedies are given. There are well selected sketches, and brief descriptions of the various types of commercial engines including the Gnome engine for aeroplanes and the Knight engine for automobiles. It is to be regretted that the author did not go more into the subject of heavy oil engines, as it is a live subject, especially for marine engineers.

The various types of gas producers are described. Diagrammatic and detailed sketches to explain principles of operation and assembled drawings of modern plants are included.

The book is recommended to all officers preparing for examination or who find their duties will require them to know something about this subject. The volume contains 145 pages, 4′′ x 7′′, and copies can be purchased from the author or through the Secretary-Treasurer of the Naval Institute; price, $1.75.

W. B. WELLS.

« EdellinenJatka »