Bevel angles can be duplicated using a sliding T bevel. The edge is sharply beveled and the bevel is typically convex. The blade is sharpened to a chisel bevel. The hypoid pinion is then larger in diameter than an equivalent bevel pinion. Zerol bevel gears are an intermediate type between straight and spiral bevel gears. Power was transmitted by a main vertical shaft with bevel gears to the horizontal shafts. The pitch surface of bevel gears is a cone. On each floor horizontal shafts engaged with the main shaft using bevel gearing. It is crosswise, coupled to both sides of the bevel pinion. A distinguishing feature is that the blade has a flat grind without a secondary bevel. In machining the word "bevel" is not used to refer to a chamfer. This meshes with another bevel gear mounted on the drive shaft. There were bevel gears on the shaft. They can also be meshed with the newer double bevel gears. Unusually the drive was by shaft and bevel gear.