Experiments upon Gunpowder. 9 



But in order that the velocity of the recoil might not 

 be too great, so as to endanger the apparatus, when 

 large charges were made use of, it was found necessary 

 to load the barrel with an additional weight of more 

 than 40 lbs. of iron. 



This additional weight of iron, which I shall call the 

 gun-carriage^ as it was so constructed as to serve as a 

 carriage to the barrel, is composed of a bar of hammered 

 iron 28 inches in length, 2.6 inches broad, and half an 

 inch in thickness, which is bent in the middle of its 

 length, in such a manner that its two flat sides or ends 

 are parallel to each other, and distant asunder two inches. 

 In the middle of this bar, where it is bent, is a hole in 

 the form of an oblong square, which, receiving the end 

 of the breech-pin, supports the lower end or breech of 

 the barrel. The other end of the barrel is supported 

 and confined in the following manner : A ring or hoop 

 of iron, near half an inch thick, and two inches in 

 diameter, is placed in a vertical position between the 

 parallel sides of the bar and near its two ends, and 

 firmly fixed to them by screws. The barrel, passing 

 through the middle of this ring, is supported upon the 

 ends of three screws, which, passing through the ring in 

 different parts of its circumference, all point towards its 

 center. * 



The carriage, together with the barrel, was suspended 

 by the pendulous rods by means of two pair of polished 

 trunnions, that are fixed to the outside of the carriage. 

 They are placed in an horizontal line perpendicular to, 

 and passing through, the axis of the bore. 



Fig. 8 represents the barrel fixed to the carriage, a^ 

 bj r, is the bar of iron seen edgeways which forms the 

 carriage. 



