“Yes, I know very well, that for basements and hard stone this is pretty sure to be attended to; but higher up your workmen are very apt to lay the stones on wedges and run the beds with liquid mortar, which is easier. Be very careful about this, Paul. All the stones ought to be laid over their place, on thick wedges, leaving a void of two and a half to three inches; the mortar ought to be spread below over the whole surface, and be about three-quarters of an inch thick; then take away the four wedges, and the stone settling down on the mortar, it must be struck with a great wooden beetle till the joint is only three-eighths of an inch everywhere, and the surplus mortar is pressed out all round——”
“Here are some hollow beds, Master Branchu; you must have them re-dressed.”
“What is a hollow bed?” said Paul to his cousin, in a whisper.
Fig. 36.
“It is a concave bed surface of a stone,” replied Eugène, and added, taking his note-book:
“Here (Fig. [36]), you can understand that if the bed of a stone presents the section A B, the middle C being more hollow than the edges, the stone in question rests on the latter only; consequently if the pressure is considerable the corners D E split off; we then say that the stone is flushed. It is better that the surfaces should be made as sketched at G, and should not rest upon their edges.
“Till now, Master Branchu, you have been raising your building by means of runs or inclined planes, but we are getting high; we shall soon want scaffolding.
“As we are building with range-work, using dressed stone above the plinth only at the angles, and for the door and window casings, you will leave scaffolding holes between these wall stones. Then you will only want scaffolding-poles and put-logs. For raising the material the carpenter is going to make you a hoist, and you will employ the crab which I shall have sent from Chateauroux, where I have no use for it just now.”
“If it’s the same to you, sir, I prefer our machine.”