Slipsheeting. to Smoothing

to Slow dryillg
.­

cord or tape on which a book is sewed. .
Slip-sheeting. (Print.) The placing of sheets of rough paper between printed sheets, so that the printed face of any sheet will not smudge the lower side of the next sheet above it. .
Slip sill. (Bldg.) A simple slab of stone of the required window width, set in the walls between jambs of the masonry opening. Easier to set than "lug sill".
Slip speed. (Aero.) The supercharger speed necessary to maintain a given pressure difference between intake and discharge when there is no air delivery.
Slip stone. (Wood Turn. alld Wood Patmkg.) A small wedge-shaped oilstone with rounded edges. It is held in the hand and used for whet­ting gouges.
Slip stream. (Aero.) The stream of air driven astern by the propeIler.
Slip washer. (Mach.) Same as open washer.
Slitter. (Prillt.) A rotary culting de­vice used on cylinder presses to deliver finished sheets in sections. It is also used on folding machines.
Slitting cutter. (Sheet-Met. Wk.) Thin rotary culters, intended forculting off, or for slilting purposes.
Slitting saw for metal. (Mach.) Thin miIling cutters used for splitting bushings, etc.
Slitting shears. (Sheet-Met. Wk.) Usu­ally a sturdy shear designed to operate by short cuts on rather heavy sheets or for cutting off rods or bars. A slitting shear may also have rotary cutters and be used for dividing a sheet into a number of strips; e.g., the dividing of a sheet of tin into a number of pieces each of a width suitable for the height of a tin can.
Slot. (Aero.) The nozzle-shaped pas­sage through a wing whose pri­mary object is to improve the flow conditions at high anlges of at­tack. It is usuaIly near the leading edge and formed by a main and an auxiliary airfoil or slat. (Wood Patmkg.) A long, narrow groove, particularly one cut to receive some corresponding part of a machanism. Slot screwing. A method of lixing whereby the screwheads arc not seen.
Slotted aileron. (Aero.) An aileron having a nose and axis arrange­ment somewhat similar to a Frise aileron but having a'smooth air passage between the nose portion of the aileron and the wing for the purpose of maintaining a smooth air flow over the upper surface of the aileron when its trailing edge is deflected downward.
Slotting machine. (Mach.) A machine used for shaping metals and cut­ting mortises, the arm which car­ries the cutters moving in a verti­cal direction.
Slow drying. (Paint and Lacquer) When a finishing material does not set up or dry hard within the dry­ing time specified by the maker, it indicates that either the surface was

Slow motion to Smoothing trowel

not clean and dry, the wrong type of reducer was employed, or the drying condtions were not normal.
Slow motion. Noting or pertaining to motion pictures in which the im­ages on the screen app~ar to move more slowly than in nature, ac­complished either by operating the camera at a higher rate of speed than in usual or by causing the projector to project a relatively smaller number of frames per second.
Slow sand filter. (Engin.) A filter for the purification of water. It is dif­ferent in construction, and is built in larger units than a rapid filter.
Sloyd knife. (Woodwk.) Knife used in the Swedish Sloyd systems of woodwork; the forerunner of the American manual training.
Sludge. Muddy deposit such as accu­mulates in a boiler. Also dirty oily deposit as in a crankcase.
Slug. (Print.) (I) A type-high bar of metal with type cast on it by the linotype. (2) Strip of metal less than type high, used as spacing material between lines of type.
Slug casing machine. (Print.) (SEE LINOTYPE; also LUDLOW.)
Sluggish. Moving slowly or having little motion.
Slur. (Print.) A blur, blemish, or smear. Slushing oil. Used to coat metals, machine parts, etc., to prevent corrosion. It usually is nondrying oil or grease which coats the metal very well but is easily removed when desired.

Slush molding. (Plast.) A method of casting thermoplastic resin into a hot mold, a skin solidifying against the mold, the remaining resin being poured out. The skin is peeled out when the mold cools.
Small caps. (Print.) Capital letters in an assortment of book type, of a smaller size than regular capitals.
Small pica. (Print.) A type size equivalent to 11 point.
Smalt. (Paint.) A vitrous sand furni­shed in various screenings and colours for painters' and sign­writers' use. It produces a brilliant ami sparkling decorative effect. Also used by painters for the protection of a painted surface subjected to wind and weather.
Smashing. (Print. and Bookbndg.) Compressing signatures to make them lay flat. Smelt. To fuse or melt the are in order to separate the metal contained. Smelter. A person who works in a place where ores are smelted.
Smelting. (Metal.) The obtaining of metal from the ore by means of heat and fluxing agents.
Smoke screen. A mass of dense smoke produced to conceal an area or to device.
Smoking. (Ceram.) The first stage of firing in which the moisture is re­moved from green ware.
Smoothing plane. (Woodwk.) A small plane usually not over 9 in. long with an iron width varying from 13/4, to 21A in. Smoothing trowel. Used by plasters and cement workers for finishing surfaces.