which it is more dangerous to break than to touch with shade the canvass surface. And, for my own part, I think a smooth, broad, freshly laid surface of gesso a fairer thing than most pictures I see painted on it; much more, a noble surface of stone than most architectural features which it is caused to assume. But however this may be, the canvass and wall are supposed to be given, and it is our craft to divide them.
And the principles on which this division is to be made, are, as regards relation of quantities, the same in architecture as in painting, or indeed in any other art whatsoever, only the painter is by his varied subject partly permitted, partly compelled, to dispense with the symmetry of architectural light and shade, and to adopt arrangements apparently free and accidental. So that in modes of grouping there is much difference (though no opposition) between the two arts; but in rules of quantity, both are alike, so far forth as their commands of means are alike. For the architect not being able to secure always the same depth or decision of shadow, nor to add to its sadness by colour (because even when colour is employed, it cannot follow the moving shade), is compelled to make many allowances, and avail himself of many contrivances, which the painter needs neither consider nor employ.
XIII. Of these limitations the first consequence is, that positive shade is a more necessary and more sublime thing in an architect's hands than in a painter's. For the latter being able to temper his light with an undertone throughout, and to make it delightful with sweet colour, or awful with lurid colour, and to represent distance, and air, and sun, by the depth of it, and fill its whole space with expression, can deal with an enormous, nay, almost with an universal, extent of it, and the best painters most delight in such extent; but as light, with the architect, is nearly always liable to become full and untempered sunshine seen upon solid
