Bronze and brass ornamental work spiral coils, and its rivet-heads (originally gold-cased) with whorls. Ordinary Mycenaean blades are enriched with narrow mouldings, parallel to the midribs of swords and daggers, or to the curved backs of one-edged knives. The spearheads have hammered sockets. Other tools and implements are oval two-edged knives, square-ended razors, cleavers, chisels, hammers, axes, mattocks, ploughshares and saws. Cycladic and mainland Greek (Helladic) weapons show no ornament but include some novel types. A tanged spearhead has a slit (Cycladic) or slipped (Helladic) blade for securing the shaft; and the halberd, a west European weapon, was in use in the Middle Helladic Greece.
Bill of quantities As the rates for materials and labour change due to inflation, these books are frequently republished.. The practice historically of estimating building costs in this way arose from non-contractual measurements, taken off drawings to assist tenderers in quoting lump sum prices. There are different styles of bills of quantities, mainly the Elemental BOQ and Trade Bills. A Contingency sum is an item found within a Bill of quantities (BoQ). The item refers to unforeseeable cost likely to be incurred during the contract. There are two types of contingency sum. The first refers to a specific item, e.g., 'additional alterations to