820 REPORT— 1886. 



motive gave the pressure of the steam in the boiler, on starting the improved engines 

 from rest on a level, to be 30 per cent, less, and on severe curves 50 per cent, less-- 

 than was required by the ordinary engine. This system is peculiarly suitable for 

 colonial locomotives. 



WEDNESDAY, SEPTEMBER 8. 

 The following Papers were read : — 



1. On recent Improvements in Sporting Ouns and their accessories. 

 By Samuel B. Allpoet. 



The writer justified the introduction to the Association of the subject of the 

 manufacture of sporting arms, on the ground of the importance of the trade to the 

 town of Birmingham, and further that the durability and performance of the guns 

 produced depends largely on the application of scientific principles to their construc- 

 tion, to a knowledge of the theory of projectiles, and of the composition and force of 

 explosive compounds. The danger and clumsiness of loading guns at the muzzle 

 have given way to the safety and convenience of using cartridges composed of defi- 

 nite charges of powder and shot, made up in a portable form and containing their 

 own means of ignition. 



The safety and shooting power of the sporting breechloader are mainly conse- 

 quent on the judicious design of its breech mechanism and the perfect fitting of 

 the surfaces in contact when the barrels are closed. The method of tQting the 

 breech ends of the barrels upwards on a hinge is most convenient to open them for 

 loading, and for firmness when closed the original fastening principle of Lefaucheux. 

 has not been excelled. The ' snap bolt ' system is, however, for home use, gene- 

 rally adopted, being more quickly manipulated and fairly durable when perfectly 

 fitted. (These systems were illustrated by drawings.) The self-acting mechanism 

 for forcing out the cartridge case was also explained. 



The safety arrangement exhibited, known as 'the rebounding lock, 'which, after 

 the gun is fired, automatically restores it to a position that renders it absolutely 

 safe from accidental discharge, was a marked advance in improvement. 



External hammers were subsequently found to be needless, and to interfere with., 

 a free aim, and hence the so-called ' hammerless ' gun was invented, wherein the 

 hammers are concealed within the gun, and the mode of working simplified. 



The ' Anson-Deeley,' and the ' Scott ' hammerless guns are perhaps the best 

 and most successful types of these guns. They possess special but different merits 

 in their mechanism and automatic safety appliances, and the disposition of their 

 moving parts is very judicious. The varieties of hammerless guns can only be 

 glanced at, as so many patents have been taken out for them in the last ten 

 years. 



In noticing the performance of shot guns it has been found that by contract- 

 ing or coning the bore of the barrel a little behind the muzzle, technically called 

 ' chokeboring,' a direction of convergence can be conferred upon the charge of shot, 

 whereby it can be concentrated upon the mark, and the tendency of the shot to 

 spread, as compared with firing it from a true cylinder, is greatly restrained. The 

 forces tending simultaneously to converge, and to disperse the charge of shot, are 

 intricate and interesting. Much of the desired effect depends on the length and 

 shape of the internal coning, for studying which the writer invented an expanding 

 micrometer for minutely measuring the variations in the boring of tubes, whereby 

 differences of calibre of half a thousandth of an inch are felt and visibly recorded. 

 This instrument was exhibited and explained. 



Latterly new gunpowders have been invented, having for their object the ob- 

 taining quickly a clear aim with the second barrel of a gun unclouded by the 

 smoke from the first barrel which arises from using ordinary black gunpowder. 

 These new powders are known as Schultze and E. C. (Explosives Company). They 



