A) The following interesting report about the Royal Artillery Barracks, Shorncliffe, (see map), was found in the Kent History Forum (link) on 20.11.2015. It is from almost exactly the same date as John Capper was stationed here (between 1853 and 1855).
Report of 1858
Royal Artillery Barracks, Shorncliffe.
These Barracks are built of brick, and were erected in 1801. They have regulation accommodation for 104 men.
There are eight soldiers’ rooms with a cubic capacity of 6,120 feet each, and as each room holds thirteen men, the space per man is about 470 cubic feet. Each room has a window back and front, but there are no independent means of ventilation. A ventilating shaft carried up fro the ceiling of each room, with means for admitting fresh air, would afford the necessary remedy.
The privies in the Barrack are in a very bad condition, and require reconstruction. They consist of a long trough, with a ladder on the top. There is a lean-to roof over this, but no other separation from the open air. The urinal is small and without water; it was offensive. The privies ought either to be converted into water latrines and drained, or else an arrangement of iron boxes with suitable means of deodorizing ought to be adopted as in the hut barracks.
The urinals also require improvement.
One of Lemprieres cooking ranges was being introduced into the kitchen at the time of our inspection. The lavatories are tolerably good, but there are no baths. Two should be provided for the purpose of cleanliness.
The rooms are rather crowded, and ought to have no more than eleven men in each.
We would recommend, therefore, in regard to this Barrack:-
1. Ventilation of each room as already pointed out.
2. Reduction of numbers to eleven men in each room.
3. Improvement in the privies and urinals as pointed out.
4. Two baths to be provided.
B) See also Wikipedia article