Q

Quadrangular Truss: Same as "Pratt Truss." -- A type of truss having parallel chords and an arrangement of web members of tension diagonals and compression verticals. See Fig. 22a.

Fig. 22a

Quadratic Equation: An equation of the second degree, or one in which the highest power of the unknown quantity is the second.

Quadruple Block: A block containing four sheaves either arranged side by side or in tandem fashion.

Quantities: The amounts of materials to be handled, expressed in the customary units.

Quarry: An excavation from which rock is obtained.

Quarry Faced Dressing: Same as "Rock Faced Dressing." -- The facing on stonework left rough as it comes from the quarry. It may be drafted or pitched so as to reduce projecting points on the face or to given limits.

Quarry Moisture: The moisture held in the pores of recently quarried rocks.

Quarry Sap: Same as "Quarry Moisture."

Quarry Water: Same as "Quarry Moisture."

Quartered Tie: A tie made from a tree of such size that four ties only can be made from a section.

Quartz: A hard, translucent mineral occurring in either crystalline or massive form. One of the constituents of granite, sandstone, and sand. Chemically, it is the oxide of silicon (SiO2).

Quay: A wharf.

Queen Post: The vertical post in a "Queen Post Truss."

Queen Post Truss: A type of trussed beam having two vertical posts.

Quenching: The hardening of steel by dipping in a liquid, such as water or oil. Sometimes molten lead is used for this purpose.

Quick Lime: The commercial lime, or a calcium oxide, which has not been hydrated.

Quick Sand: A fine, smooth-grained sand. A very fine, silt-like sand saturated with water so that it has no stability.

Quick-setting Cement: A cement that sets between five minutes and thirty minutes after mixing.

Quiescent Load: A load that is not in motion.

Quirk: An acute angle or recess. A deep indentation. The incision under the abacus.

Quoin: An exterior solid angle in masonry. A wedge-like piece of stone or metal. To wedge or raise up.