(Hi) Materials.?The aggregate may be made with 1 part of cement and 3 to 4 of sand, or 1 of cement with 1 of sand and 3 of coal ashes. Iron wire l/8th to 1/16th inch in diameter should be used in every limb, bar or curve of the window. Kerosene oil is good enough for lubricating the mould. Moulds should be emptied, i.e., windows cast, on a layer of sand, spread out and levelled, to prevent stic...