94 ANNUAL OF SCIENTIFIC DISCOVERY. 



If these suggestions are followed out, with others which the ad- 

 vancement of knowledge will indicate, the author believes that Amer- 

 ican iron, manufactured from magnetic ores, will not only drive Rus- 

 sian, Norwegian, and Swedish iron from our own market, but compete 

 with those nations in that of Great Britain. 



NEW COMPOUND RAIL. 



IN the subdivision of railroads, two patents for improved compound 

 rails deserve notice. The construction of one of these may be de- 

 scribed as follows. Saw or split in two any line of ordinary T rails 

 in the direction of their length, which would leave, besides the usual 

 openings at the junctions, another slit the whole length of the track 

 from top to bottom of the rail ; tha draw one set of halves in either 

 direction, until the junctions between its parts come midway between 

 the junctions of the other sot, and bolt the whole together by transverse 

 bolts. A compound break-joint rail is thus formed, preventing to a 

 great extent the jar experienced in passing from one rail to another, 

 and rendering them less liable to be thrown from their proper place 

 on the track. The other rail may be styled an improvement on this 

 one. It has the same peculiarities, but in addition, the sets of halves 

 are formed in such a manner as to leave a continuous hollow or tubular 

 space the whole length of the rail, into which are inserted at the junc- 

 tions, iron cores, rendering the rail firmer at these weak points. It 

 differs likewise in its exterior form, its cross-section being such as 

 would be produced by rounding off the corners of a parallelogram, 

 and bending in all its sides. The rail is thus, as it wears, susceptible 

 of four reversals. A chair peculiarly fitted for supporting it forms a 

 part of the invention. Patent Office Report, 1849. 



IRON AS A MATERIAL FOR SHIP-BUILDING. 



MR. GRANTHAM, in a paper read before the Liverpool Polytechnic 

 Society, after alluding to the many advantages to be derived from the 

 use of iron as a material for ships, and the difficulty caused by their 

 bottoms becoming foul, which has hitherto prevented its general use, 

 proposes to cover the iron with wood. This he does by placing the 

 ribs of the vessel on the outside of the iron, over which a thin sheath- 

 ing of wood is laid, and coppered in the usual manner. London Min- 

 ing Journal. 



THE EFFECT OF SHOT AND SHELLS ON THE HULL OF IRON 



VESSELS. 



EXPERIMENTS for testing the effects of shot and shells on the sides 

 of iron vessels have recently been instituted, under the direction of 

 government, at Portsmouth, England, in the presence of large num- 

 bers of military and scientific men. A large butt had been made in 

 the dock-yard, representing the two sides of an iron vessel, each side 

 of the strength and consistency of one of the large iron steam-ships. 



