170 
SHORT NOTES ON PROFESSIONAL SUBJECTS. 
This appears to be the simplest description of machine for driving the pickets 
which it is necessary to use when making holdfasts for sheers with which to lift 
guns of 12 tons and upwards. 
The holdfast is thus constructed, agreeably to Minute 
Gen. No. 5 # 
5288 
A hole ( b , h,f 3 g) 15 ft. x 4 ft. X 4 ft. is dug, and four planks (5, 5, b , b) placed 
on edge against the side nearest the points from which the strain is to come. 
Four pickets, 8 ft. X 6 ins. diameter (one shown at “ a ”), are driven behind the 
planks at intervals 8 ft. 6 ins. apart, to a depth of 8 ft. below the bottom of the 
trench. 
One-third of the trench is now filled in, and a beam about 15 ft. x 12 ins. x 12 ins. 
(c)—an old gun will answer—is placed horizontally against the four pickets. 
The centre of a chain, 1 in. or more in diameter, is fastened round the centre of 
the beam, and the two ends are brought between the second and third planks, 
through a narrow trench cut at right angles to the original one, to the surface; 
the trenches are then filled in, and the strain taken in the two ends of the chain. 
Spars for sheers to lift 25-ton guns should be 45ft. in length and 20 ins. 
diameter in centre. 
^IFor 12-ton guns, with spars of 45 ft., 17 ins. at the centre; with spars of 40 ft., 
16 ins. 
109. New Wrought-iron Field Artillery Carriages. 
(Communicated by Captain W. Kemmis, R.A.) 
A short description of the following field artillery carriages may not prove 
uninteresting, as they are likely to supersede the present service patterns, in future 
manufacture, viz.:— 
Nature. 
Weight empty. 
Tonnage. 
9-pr. M.L.R. gun-carriage . 
cwt. qr. lb. 
10 2 17 
10 3 16 
14 O 1 
10 3 16 
12 1 24 
11 0 22 
14 1 13 
11 0 22 
tons. 
| 4*079 
| 4*493 
j 4*079 
j 4*493 
ii limber . 
n wagon . 
n limber . 
16-pr. M.L.R. gun-carriage . 
« limber . 
// wagon ... 
n limber . 
---— - ..... ...- ■ .. 
9 -pr, M.L.R. Gun-Carriage . 
The main points of difference between this and the present service carriage, are 
as follows:— 
The substitution of a wrought-iron for a wooden axletree-bed; the construction 
of the brackets, in which the plate is placed on the inner instead of the outer side 
of the bracket frame; and the form and manner of the connection of the trail plate. 
