granites of Dartmoor to porcelain clay bind the sands of Coventry into stones which can be built up half-way to the sky.
153. But now, as to the matter immediately before us, observe what a double question arises about laying stones as they lie in the quarry. First, how do they lie in the quarry? Secondly, how can we lay them so in every part of our building?
a. How do they lie in the quarry? Level, perhaps, at Stonesfield and Coventry; but at an angle of 45° at Carrara; and for aught I know, of 90° in Paros or Pentelicus. Also, the bedding is of prime importance at Coventry, but the cleavage at Coniston.[1]
b. And then, even if we know what the quarry bedding is, how are we to keep it always in our building? You may lay the stones of a wall carefully level, but how will you lay those of an arch? You think these, perhaps, trivial, or merely curious questions. So far from it, the
- ↑ There are at least four definite cleavages at Coniston, besides joints. One of these cleavages furnishes the Coniston slate of commerce; another forms the ranges of Wetherlam and Yewdale crag; a third cuts these ranges to pieces, striking from north-west to south-east; and a fourth into other pieces, from north-east to south-west.
