AMERICAN INSTITUTE. 271 



First the engine, with a sufficiency of water for a good long 

 yoking, weighing nine tons, hauled a heavy siege gun, (5 tons 12 

 cwt.) carriage and tender (2 tons 7 cwt.) and sixteen men (say 1 

 ton 2 cwt), making a total of 18 tons, including the engine itself, 

 from the arsenal up Barrage road to Plumstead common, and 

 down the steep incline to Waterman's fields in return. The 

 steepest part of the ascent is one in ten, and of the descent one in 

 eight, both inclinations having to be re-measured. Of the two, the 

 descending was considered by all present the master-part of this 

 experiment, no brake or drag being upon any part of the wheels, 

 those of the gun-carriage and tender, (9 tons,) being without end- 

 less rails, for in the very steepest part of the inclination, our 

 modern megatherium (great wild beast,) war-horse had as much 

 control over his ponderous load as is to be seen in the parallel 

 case of the steam-hammer, standing rock-fast, like a statue, the 

 instant the order " stop her " was given — a feat which even few 

 of the admirers of this new-fangled innovation expected to see 

 performed in so triumphant a manner. Moreover in going up 

 Barrage road, the wheels of the gun carriage sunk from one to 

 three inches in the shingle of which the road was made — a cir- 

 cumstance which greatly added to the draught; nevertheless the 

 war-horse dauntlessly took the ascent with that dignity of bearing 

 and self-confidence which characterises the genius of steam when 

 master of its work, and would soon have enabled the men to have 

 planted the huge gun on the top of Shooter's hill, had not Colonel 

 Tullock ordered him down the steep descent to try his metal there. 



The second experiment was in hauling a gun of the same size 

 over a marshy bog, in the lower part of the arsenal grounds, a 

 bog too soft to bear the feet of horses when pulling, or even when 

 standing. The wheels of the gun-carriage, in this case, were fur- 

 nished with rails, and the engine was yoked to the gun by means 

 of a rope, capable (it was said) of sustaining a strain of ten tons. 

 This rope was broken by fair pulling several times, owing to 

 abrupt inequalities in the ground which the wheels were run 

 against, and not the best of engineering; but these were even- 

 tually both overcome. Two thousand and forty pounds pressure 

 of steam on both pistons, or sixty pounds to the square inch, drag- 



