98 REPORT— 1844. 



steamers was effected by the J. M. White, in the summer of this year. She made her 

 way against an average current of from 3 to 4 miles an hour, from New Orleans to 

 St. Louis, a distance of 1200 miles, in 3 days and 23 hours, remaining a day and a half 

 at St. Louis, unloading and loading, and reached New Orleans again, having performed 

 a distance of from 2300 to 2400 miles in little more than 9 days. The average speed, 

 taking advantages and disadvantages into consideration, would be 16 miles, or perhaps 

 near 14 knots per hour. 



On the New Double Piston Steam-Engine, with a Model. 

 By J. G. BoDMER. 



The advantages claimed are velocity, ceconomy, peculiar expansion, diminution of 

 strain upon the axle, &c. 



On the (Economy of the Expansive Action of Steam in Steant'Engines. 

 By W. Fairbairn. 



On Propelling Boats. By Mr. Smith. 

 In this communication the jet plan was advocated. 



Mr. Gray enumerated a variety of experiments on iron bars, with a view to show 

 that the want of due proportions in the several parts is productive of more or less 

 danger. 



Mr. J. Buchanan offered some observations on a new locking apparatus for car- 

 riages, which he illustrated by models. The suggested improvement arises from the 

 introduction of the double pivot, which requires less room to turn the front wheels, 

 and consequently gives increased space to the body of the carriage. He also exhibited 

 some carriage springs, the improvement in which was effected by the introduction of 

 leather packing. 



On a Plan for drawing Coals from Pits witliout Ropes or Chains. 

 By E. BowNESs. 



The advantages claimed are oeconomy, durability, expedition, and compactness. 

 The plan has some resemblance to a method which has been adopted in Cornwall for 

 the purpose of raising and lowering the miners. The corves, holding each 10 cwt. of 

 coal, slide in grooved rods fixed on the sides of the shaft, and are alternately seized 

 and released by lifters attached to a rod which moves up and down in the centre of 

 the pit by engine power ; when released from the rod on its downward motion, the 

 corves are supported by a self-adjusting pulley. 



On a Neto Apparatus for Starting Heavy Machinery. By J. G. Bodmer. 



Upon the driving-shaft a bevel wheel is fixed at one end, and another is put on 

 loose opposite to it, with a pinion between. To the latter is fixed another bevel 

 wheel, and this gears into a pinion which is connected with the shaft driving the ma- 

 chine to be started. By applying the break to the drum to which the centre of the 

 intermediate pinion is fixed, the machine attached will be set in motion. 



On Niasmyth's Steam Pile Driver. By Dr. Green. 



Mr. Whitworth exhibited a new machine for ascertaining the diameter of metallic 

 cylinders. 



On a Neiv Furnace Grate. By J. G. Bodmer. 



The peculiarity of the fire grates is, that the fire bars are made to travel from the 

 fireplace or hopper towards the bridge, and return again to the place whence they 



