17. What changes have been recently made in the construction and sighting of 
the 12-pr, Armstrong gun? Do these changes involve any practical alterations as 
regards working the gun ? What improvements has Lieut. Beeves made in the 
ammunition ? 
18. Why is it necessary to “face” Armstrong guns and vent pieces from time 
to time ? Sketch the tools used in this operation. Explain briefly how it is per¬ 
formed, and the consequences of neglecting it. 
19. What strains is a rifled gun subject to on firing? 
20. What parts of a gun in general first shew signs of weakness? How is the 
exact position and extent of damage ascertained, and to what causes may it be 
attributed ? 
21. State approximately what every 100 yds. of range is represented by on the 
tangent scale of an Armstrong 12-pr. gun, and the value of each minute on the 
deflection scale per 100yds. of range? Is this value the same with all charges? 
22. In what manner has Colonel Boxer improved the construction of rockets, 
and what advantage does Mr Hale claim for his system ? 
28. What do you understand by the term “ penetration ? ” TJpon what does it 
depend ? 
24. Mention some of the principal dimensions of a cast-iron 68-pr. and a 7-in. 
gun; the charges of powder; windage; length of bore; length of cartridge; 
initial velocity; weight of gun to weight of shot; recoils and elevations due to 500, 
1000, and 1500 yds. range. 
25. Write down in a tabular form the bursting charges of the 13, 10, 8, and 
7-in common shells, and of the 8-in. and 32-pr. diaphragm shells. 
26. What platforms have you constructed here ? Explain the mode of laying 
them. Mention their respective advantages or otherwise ; the services for which 
they are intended ; the number of men and intrenching tools required to lay them, 
and name the platform best suited to the rear chock carriage. 
27. What number of rounds are taken into the field with the Armstrong 12-pr. 
gun, and how are they distributed ? What additions have lately been made to the 
boxes, and what alteration in the trail ? 
28. Describe the particular operations you conducted with field guns, at the 
practical examination. Were you quite successful, or if you had the work to 
perform again, would you from experience gained, suggest any other mode of pro¬ 
ceeding ? 
29. There are two classes of traversing platforms. How is the one converted 
into the other ? Describe the sliding carriage used with them, and state why a 
compressor has been added of late ? What does Lieut. Thornhill propose in the 
new construction he has just brought forward? Explain the terms “imaginary 
pivot ” and “raised racers,” and the present difficulties connected with the latter. 
30. How is the naval slide laid down and worked? What improvements have 
been recently made in its construction ? 
31. Describe briefly the triangle gyn, its object and uses, and the number of 
men required to work it. Have you known of any accidents in using it here or 
elsewhere ? If so to what were they attributable ? 
32. In raising a 6 ton gun by triangle gyn, what size of fall would you prefer 
and why ? and what dimension and nature of blocks ? What power must be applied 
to the ends of the levers ? 
33. In mounting a 68-pr. gun up the rear of a sliding carriage on a dwarf 
platform, shew by sketch what arrangements you would make, and state what 
tackle and other stores you require. Explain how the movement of the gun is- 
affected by the position of the rollers, and the relative rate of motion of each; and 
why this particular manoeuvre,—mounting up the rear—is unsuited to 7-in., and 
other guns of a similar exterior form. 
