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I. ARCHITECTURE.—[Evolution of the Modern Mill.]—By C. J. H. Woodbury.—Continuation of this Sibley College lecture, treating of the practical details of mill structures.[10346]
II. ASTRONOMY.—[Changes in the Stellar Heavens.]—By J. E. Gore, F.R.A.S.—Changes of color, brightness, and position in the fixed stars as attested to by the records of the ancient and modern astronomers.[10355]
[Distance and Constitution of the Sun.]—Modern theories of the sun and difficulties in formulating a satisfactory explanation of all of its phenomena.[10354]
III. BOTANY.—[The Common Dandelion.]—By Frederick Leroy Sargent.—The properties and life history of this common plant.—Its wonderful seed-distributing apparatus.—8 illustrations.[10355]
IV. CHEMISTRY.—[Poison of the Somalis extracted from the Wood of the Ouabaio.]—A recently investigated plant principle.[10358]
V. CIVIL ENGINEERING.—[Test of a Wrought Iron Double Track Floor Beam.]—By Alfred P. Boller.—A test pushed to actual rupture of a full-sized member of a bridge.—1 illustration.[10344]
[Timber and Some of its Diseases.]—By H. Marshall Ward.—Part V. of this exhaustive treatise of the deterioration of one of the great structural materials.—1 illustration.[10345]
[Improved Torpedo Boat.]—1 illustration.[10348]
VI. ELECTRICITY.—[Effect of Chlorine on the Electro-motive Force of a Voltaic Couple.]—By D. G. Gore, F.R.S.—A very curious investigation, disclosing the sudden change in E. M. F. produced by a definite addition of chlorine.[10351]
[On a Theory Concerning the Sudden Loss of Magnetic Properties of Iron and Nickel.]—By Mr. A. Tomlinson, B.A.—A new theory, involving the probable rearrangement of the molecules or "magnetic atoms" of the metals in question.[10358]
[The Passive State of Iron and Nickel.]—Note of this curious phenomenon.[10347]
[The Wimshurst Electric Machine.]—Illustration of 13½ inch sparks produced by it.—1 illustration.[10352]
[The Application of Electricity to Lighting and Working.]—By W. H. Preece.—Lecture I.[10350]
VII. ENTOMOLOGY.—[Systematic Relations of Platypsyllus as determined by the Larva.]—By Dr. C. V. Riley.—An important contribution to entomological science, a paper read at the meeting of the National Academy of Science, April 20, 1888.—4 illustrations.[10356]
VIII. HYGIENE.—Reducing Obesity—Note of general principles to be applied to diet and life. {Transcriber: Omitted by publisher.}[10352]
[The Care of the Eyes.]—By Prof. David Webster.—A practical and scientific examination of how to preserve the eyesight and of the use and abuse of this important organ of sense.[10352]
[Sanitation in Massachusetts.][10352]
IX. MECHANICAL ENGINEERING.—[Hydraulic Tube Press].—An extraordinarily powerful press for striking up tubes from flat plates.[10345]
[The Distribution of Hydraulic Power in London.]—A recent system introduced in London, with description of the plant and distribution pipes.[10344]
[The One Hundred and Twenty Ton Shears of the Port of Marseilles.]—An immense set of hoisting apparatus described and illustrated.—3 illustrations.[10343]
X. PHOTOGRAPHY.—[Colored Photography.]—Mr. J. E. Mayall's recent advances in this phase of photography.[10349]
XI. PHYSICS.—[Scientific Apparatus at the Manchester Royal Jubilee Exhibition.]—Notes of the most interesting electrical, photometrical, and communicating apparatus.[10348]
[The Spectra of Oxygen.]—Interesting investigations of absorption spectra of oxygen.[10358]
XII. SURGERY.—[Papillomatous Tumor of the Bladder, demonstrated by Means of Lister's Electro-cystoscope.]—By F. N. Otis, M.D.—An interesting instance of the use of an exploratory electric light.—2 illustrations.[10354]
[Tumors of the Bladder Diagnosed by Means of the Electro-Endoscopic Cystoscope.]—By Dr. Max Nitze.—The same general subject in further detail, giving the German practice.—5 illustrations.[10353]
XIII. TECHNOLOGY.—[Future Prospects for Gas Companies.]—By Mr. Thos. Wood.—Fuel and oil gas and the future Utopia of improved gas manufacturing.—The ideal gas company of after days.—A valuable and suggestive paper.[10349]
[Advertisements.][10358]

THE ONE HUNDRED AND TWENTY TON SHEARS OF THE PORT OF MARSEILLES.

For a quarter of a century maritime nations have been continuously engaged in improving the mechanical appliances of their large ports. The use of tracks to bring goods to be placed on vessels as near as possible to the shipping point, the substitution of oblique moles for perpendicular ones in large docks, the creation of a hydraulic method of loading and unloading through movable cranes (which will perhaps in a near future cede to an electrical one), constitute the means most used for expediting transshipments and reducing the expense of them to a minimum. But, at the same time that the facilities for all kinds for handling packages have been increased, it has also become necessary to greatly increase the power of the machines applied to them. The construction of large packets now requires the putting in place of boilers of great weight, and the adoption of the huge pieces that compose the artillery of ironclads necessitates the use of force that has been unknown up to recent times.

Fig. 1.—DIAGRAM OF SHEARS.

Fig. 2.—ONE HUNDRED AND TWENTY TON SHEARS OF THE PORT OF MARSEILLES.

At present, then, we could no longer be content with manual power, acting upon windlasses or capstans, for lifting and shifting. It has become necessary to apply steam or hydraulic motors to these operations. Of these, the latter are the most used, on account of their easy operation and their submitting to the greatest stresses with a very satisfactory proportionality of the expenditure of motive power. One of the most remarkable of such apparatus is the one that the Compagnie de Fives-Lille has recently set up on one of the moles of the national dock at Marseilles, for the service of the chamber of commerce, and this merits a description so much the more in that it is an important improvement upon the analogous apparatus now in use in other ports.

According to the conditions of the programme, powers of 25, 75, and 120 tons had to be obtained at will, with a proportional output of water, and the load had to be lifted 22 ft. above the quay and carried horizontally from 28 ft. beyond the edge to 16 ft. in the rear, so that the load might be taken from a ship and deposited upon a wagon, and vice versa. The shears, then, had to be capable of performing two operations, viz., of lifting the load and of carrying it horizontally. To facilitate the description, we shall first make known the arrangements that assure the second operation.