The slate in Pennsylvania for a new roof is still split into roofing shingles by hand, and the blocks are kept wet with water during the splitting process to enhance the ease of splitting. The stone is said to split with much greater ease when the quarry sap is not allowed to evaporate. It is an opinion echoed by slate workers in Wales and elsewhere in Europe, who insist that slate blocks left out on the surface of the earth to dry will not split as readily as freshly quarried slate. The splitting of slate into the right thickness for roofing shingles may not entirely be the responsibility of the splitter, but may involve the block cutter and the blacksmith. The block cutter can split the incoming block to the proper thickness to allow for a predetermined number of slates to be produced from one slab. Since the standard thickness of a roofing slate is 3/16", the slab should be a factor of that thickness. In order for the block cutter to consistently split a block to the thickness desired, his chisel is conveniently made to the proper width and can be used as a measuring tool as well as a chisel.