In the Greek period, very elaborate techniques for casting bronze sculptures were used. Several techniques of the lost-wax process were known. The foundry was a technically well-established place, normally with a deep pit to keep the mold. Special devices to collect the molten wax have been found. Normally, more than one object was cast at once to save time, since the soil has to be removed from the pit after casting. The kilns for melting the metal were large and furnished by installations to increase the heat of the fire. Larger objects, which had been cast in separate pieces, were assembled close to the foundry. Also, the surface of the object was finished in the working area.