On the size of bricks and maker’s marks:

The size of bricks also matters in the message they send. The great historian of bricks, Alec Clifton-Taylor, observes that what most counts about them is their small size, which just suits the human hand laying a brick. A brick wall, he says, “is therefore an aggregation of small effects. This implies a human and intimate quality not present to the same extent in stone architecture.” Clifton-Taylor further observes that brickwork imposes “a certain restraint…brick is anti-monumental…the smallness of the brick unit was not in tune with the grander…aspirations of the Classicist.”

“An aggregation of small effects” recalls E.F. Schumacher’s refrain that because humans are small, small is beautiful. Furthermore:

Ancient brick workers who labored on the classical empire’s most grandiose projects still held in their hands a material with quite a different physical implication, and it was with this material that the anonymous slave brickmaker or mason made his presence known. The historian Moses Finlay wisely counsels against using a modern yardstick to measure maker’s marks as sending signals of defiance; they declare “I exist,” rather than “I resist.” But “I exist” is perhaps the most urgent signal a slave can send.