38 ANNUAL OF SCIENTIFIC DISCOVERY. 



reasons are given for its superiority over other machines of the same 

 sort. It can be worked for about a quarter of the expense of rail- 

 ways, though of course not at so great a speed as is attained on the 

 latter. 



IMPROVEMENTS IN LOCOMOTIVES. 



THE London Mechanics* Magazine describes some newly patented 

 improvements in locomotive engines and in marine and stationary en- 

 gines. They consist, 1st, in converting reciprocating rectilineal mo- 

 tion into rotary motion ; and 2d, in converting rotary motion into re- 

 ciprocating rectilineal motion. 1. Upon the revolving shaft is fixed 

 at right angles a lever, to the other end of which, and on one side, is 

 attached a small rectangular block. On that side of the lever which 

 carries the block is a square metal plate containing two slots, one 

 horizontal and the other vertical, which intersect at right angles in the 

 centre of the plates. The revolving shaft passes through the vertical 

 slot, so that the plate may travel freely up and down over it. The 

 block (which is somewhat longer than the breadth of the vertical slot) 

 is placed in the horizontal slot. Supposing the lever to be upright, 

 slightly deviating from the perpendicular, which is parallel to the ver- 

 tical slot, and that a downward motion is communicated from a steam- 

 engine to the plate, to the full extent of the vertical slot, the result 

 will be that the block will travel from the centre to the end of the 

 horizontal slot, that the lever will assume a position the reverse of the 

 one in which it was first placed, and that the main shaft will have 

 made half of an entire revolution. The dead centre is then overcome 

 by a fly-wheel, and an upward motion given to the plate, whereby 

 the revolution of the main shaft is completed, and the lever brought 

 back to the first position ready for the second operation. 



2. The arrangements for converting rotary motion into reciprocal 

 rectilineal motion are the reverse of those above described. When 

 the rotary motion is to be communicated to the end of a crank-shaft or 

 crank-pin upon a wheel, the vertical slot may be dispensed with, and 

 the horizontal one only used, or a groove may be substituted for the 

 slot. 



IMPROVED LOCOMOTIVE BOILERS. 



AT the meeting of the Institution of Mechanical Engineers in Lon- 

 don, on July 25th, Mr. Ramsbottom, of Manchester, read a paper 

 " On an Improved Locomotive Boiler." He began with some intro- 

 ductory observations on the fact, that the absolute power of the loco- 

 motive is directly proportioned to the quantity of steam which the 

 boiler can produce in a given time. All recent improvements in boil- 

 ers have been tending to obtain a greater amount of heating surface 

 without increasing the length or diameter of the boiler, or making it 

 oval. To effect this object the author proposes to construct a copper 

 fire-box with an arched roof, whose top would be nearly as high as the 

 cylindrical part of the boiler. With such a box the whole of the 



