There are many Precautions to be given to make the Masonry more firm and durable, and these Precautions are common to all the different sorts of Masonry.
Lib. 1.
Chap. 5. When you would have the Walls very thick, for great and heavy Buildings, you must strengthen the inner part of the Wall with long Piles of singed Olive, which serves for Keys and Braces, for this Wood being so prepar'd never corrupts.
Lib. 6.
Chap. 11.
Vide Index. It is likewise of great Importance for the strength of Walls, that all be directly Perpendicular, and that the Chains, the Pillars and Pieds-droits or Piers be so situated, that solid always answer'd to the solid; for if there be any part of the Wall or any Pillar that carrys false, it is impossible the Work should continue long.
There are also two ways of strengthning the Walls, which are either to ease them of their own weight, or of that of the Earth which they are to support.
The first way of easing is in those Places where there are void spaces, as above Doors or Windows. These easements may be made two different ways; the first is to put over the Lintel which supports the Wall, which is over the void space of the Gates and Windows, two Beams, which lying or resting below directly upon Pieds-droits or Piers meet together above.
The other way is, to make directly over the void spaces Vaulted Arches with Stones cut corner-ways and tending to one Center. For the Walls be so strengthned by the means of these easements, that part of the Wall which is below will not sink at all being easied of the load of the part that is above, and if some defect should happen by tract of time, it may be mended without propping that which is above.
The second way of easing, is, for Walls that are made to support the Earth; for, besides the extraordinary thickness which they ought to have, they should have likewise Buttresses on that side next the Earth, so far distant one from another as is the breadth of the Wall; they ought likewise to have an Emparement or large Foundation which must be equal to the height of the Wall, so that they go diminishing by degrees from the bottom to the top, where they come to equal the height of the Wall.
Lib. 1.
Chap. 5. The effect of these Buttresses is not only to support the Earth by their Resistance, but likewise to lessen its Efforts when it swells, in dividing it into many parts.
Lib. 6.
Chap. 11. And it be judg'd that these Buttresses be not sufficient, the Wall also which supports the Earth must be strengthned with other Buttresses within.