NEW YORK, MAY 28, 1887

Scientific American Supplement. Vol. XXIII, No. 595.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.


TABLE OF CONTENTS.
I.[BOTANY.—The Relation of Tabasheer to MineralSubstances.—The composition of this curious secretion of thebamboo.—Analyses and properties of the material, according tovarious observers.—Its appearance under the microscope. 1illustration.]
II.[CHEMISTRY.—Apparatus for DryingFlour.—An apparatus for determining the moisture in flour. 1illustration.]
III.[ELECTRICITY.—Automatic Commutator forIncandescent Lamps.—An apparatus for lighting automatically anew lamp to replace one that has failed. 1 illustration.]
[Definitions and Designations inElectro-Technics.—Mr. Jamieson's proposed code of electricsymbols—literal and graphic. 4 illustrations.]
IV.[ENGINEERING.—New DredgingMachinery.—The dredger Ajax, recently built inCalifornia.—Its dimensions and capacity. 1 illustration.]
[Reservoir Dams.—By DAVID GRAVELL.—Theengineering details of dams.—Typical masonry and earthworkdams of the world. 23 illustrations.]
[The Flexible Girder Tramway.—A new type ofsuspended railway—a modification of the wire tramway system.21 illustrations.]
V.[HYGIENE.—Climate in its Relation toHealth.—By G.V. POORE, M.D.—The third lecture of thisseries.—Consideration of the floating matter of the air anddiseases caused thereby.—Causation of hay fever.]
VI.[MATHEMATICS.—Radii of CurvatureGeometrically Determined.—By Prof. C.W. MACCORD,Sc.D.—No. VII. Path of a point on a connecting rod. 3illustrations.]
VII.[MICROSCOPY.—Improved Microscopical SettlingTube.—By F. VANDERPOEL.—New tubes for use in urinaryanalysis. 4 illustrations.]
VIII.[MISCELLANEOUS.—Apparatus for ManufacturingBouquets.—An ingenious machine for facilitating theconstruction of bouquets. 1 illustration.]
[Bozerian's Refrigerant Punkas.—A fan workedby the feet, a substitute for the Indian punka. 2illustrations.]
[How to Make a Kite without a Tail.—Animproved form of kite described and illustrated. 1illustration.]
[Punkas.—By J. WALLACE, C.E.—Themechanics of punkas; experiments on their rate of swing.]
[The Edible Earth of Java.—An account ofthis curious substance, its taste and appearance.]
IX.[NAVAL ENGINEERING.—Another RemarkableTorpedo Boat.—Over twenty-eight miles an hour.—Fullparticulars of the trial of one of the new Italian torpedo boats,built by Yarrow & Co.]
[Copeman & Pinhey's Life Rafts.—A newlife raft for use on steamers, folding into deck settees. 3illustrations.]
X.[PHYSICS.—Sunlight Colors—By Capt. W.DE W. ABNEY.—A valuable lecture on the cause of the colors ofthe sun, and their relative intensities. 3 illustrations.]
[The Wave Theory of Sound Considered.—ByHENRY A. MOTT, Ph.D., LL.D.—Arguments against the generallyaccepted theory of sound.]

COPEMAN & PINHEY'S LIFE RAFTS.

The experiments with life saving appliances which Mr. Copeman brought before the delegates of the Colonial Conference, on the 13th April, at the Westminster Aquarium, had a particular interest, due to the late and lamentable accident which befell the Newhaven-Dieppe passenger steamer Victoria. In many cases of this nature, loss of life must rather be attributed to panic than to a want of life saving appliances; but, as a general rule, an abundant supply of such apparatus will tend to give passengers confidence, and prevent the outbreak of such discreditable scenes on the part of passengers as took place on the Victoria.

FIG. 1.—COPEMAN & PINHEY'S LIFE RAFTS.

Messrs. Copeman & Pinhey have, for some years past, done good work in this direction, and at the recent meeting of the Institution of Naval Architects, Mr. Copeman showed several models of the latest types of their life saving apparatus, both for use on torpedo boats and passenger steamers. Our illustration (Fig. 1) represents the kind of rafts supplied to her Majesty's troop ships, while Figs. 2 and 3 show deck seats convertible into rafts, which are intended for ordinary passenger steamers. The raft shown in Fig. 1 consists of two pontoons, joined by strong cross beams, and fitted with mast, sail, and oars. When not in use, the pontoons form deck seats, covered by a wooden grating, which in our illustration forms the middle part of the raft. Each pontoon has a compartment for storing provisions, and when rigged as a raft, there is a railing to prevent persons being washed overboard.

FIG. 2.

FIG. 3.

The seat life buoy, shown in Fig. 2, serves as an ordinary deck seat, being about 8 ft. long, and it consists of two portions, hinged at the back. When required for use as a life buoy, it is simply thrown forward, the seat being at the same time lifted upward, so that the top rail of the back engages with the two clips, shown at either end of the seat, and the whole structure then forms a rigid raft, as will be seen from Fig. 3. Several other appliances were shown at the Westminster Aquarium on April 13, but the two rafts we have selected for illustration will give a sufficiently correct idea of the general principles upon which the apparatus is based.—Industries.