CLAMP is likewise the term for a pile of unburnt bricks built up for burning. These clamps are built much after the same manner as arches are built in kilns, viz. with a vacancy betwixt each brick's breadth for the fire to ascend by; but with this difference, that instead of arching, they trust over, or over-span; that is, the end of one brick is laid about half way over the end of another, and so till both sides meet within half a brick's length, and then a binding brick at the top finishes the arch.