L to Laminar flow

L to Lacunar

I. Symbo.l fo.r length, litre, wavelength. L. Symbo.l for inductance, relative heat
constant.
L.bead engine. (Auto.) Takes its name from the shape of a section through the head. It is a very popular com­pact type o.f mo.to.r with all valves, cams, valve lifters, and other mo.v­ing parts enclosed.
Label. (Arch.) A projecting mo.lding or dripstone over an o.pening in a wall.
Label paper. (Papermkg.) A paper adequately sized fo.r making labels.
Laboratory. A place where scientific tests, experiments, analysis, etc., are carried o.n. .
Laboratory assistant. A junior engi­neer who.se work consists of routine testing o.f materials.
Labor saving. (Prillt.) Printing mate­rials prepared fo.r quick use and saving o.f time.
Labyrinth. Type oflo.ud-speaker cabi­net with partitio.ns producing a lang, co.nvoluted path between rear o.f drive unit and outlet po.int. Lined with damping material to. co.nfine reso.nant effects to. LF.
Lac. (Wood Fill.) Often co.nfused with shellac. Lac is the secretio.n o.f the lac insect, while shellac is a prod­uct manufactured fro.m it. The name is frequently applied to. quick-drying wo.o.d finishes.

Lacewood. So.metimes called silky o.ak: Native o.f Australia. An inex­pensive but decorative wo.o.d marked with small evel1ly distrib­uted silky spo.ts. Used generally in small surfaces and inlays.
Lacing. (Ellgill.) Bars placed diago­nally to. space and stiffen mem­bers, as in a built-up column.
(Mech.) The fastening together o.f the ends of a belt with laces, usu­ally o.f rawhide; metal fasteners, ho.wever, are now largely used fo.r the purpo.se.
Lacquer. (Metal Fin.) A varnish applied to. metalwo.rk to. protect it fro.m the tarnishing influence af the atmosphere or from handling.
Lacquer work. (Furn.) Work coated with lacquer to. prevent tarnish­ing; o.r decarative wo.rk lacquered in imitatian af enamel.
Lactometer. An instrument fo.r de­termining the specific gravity o.f milk.
Lactoscope. An o.ptical device far determining the amaunt o.f cream in milk.
Lactose. (Chern.) Milk sugar. (CI2H2PIl) Impalpable, sweet, white po.wder, derived from whey by co.ncentratio.n and crystalliza­tian. Used in infant fo.o.ds and medicines.
Lacunar. (Arch.) A paneled ar

Ladder to Laminar flow
coffered ceiling.
Ladder. (Bldg.) An aid to climbing. Usually made of two parallel up­rights connected by regularly spaced rungs.
Ladder back. (Furn.) A chair back having several horizontal slats.
Ladle. (Fdry.) Receptacle used for tak­ing the molten metal from the cu­pola. in transporting it, and in pour­ing it into the molds. Ladles are of various shapes and sizes with ca­pacities from 25 pounds to 100 tons.
La Fargecement. (Bldg.) An imported nonstaining by-product cement pro­duced during the calcination of hydraulic lime. It develops nearly the same strength as the Portland cements.
Lag. (Elec.) A retardation. A sine curve lags another curve when its minimum and maximum points are r~ached later than the similar points on the other curve.
Lagging current. (Elec.) Inductance in an electrical circuit causes the current to lag the voltage.
Lag screw. A square-headed, heavy wood screw. It must, be tightened down with a wrench as its head is not slotted.
Laid paper. (Paperrnkg.) Any paper containing a watermark which appears as a series of parallel lines, caused by the press~re of the dandy roll on which the wires are parallel.
Lake. (Chern.) A compound of a dye with a mordant.
Lake copper. (MetaL) Is obtained by wet concentrating methods from the ores found near Lake Michi- . gan.
Lambert. The centimeter-gram-seC­ond unit of luminance or bright­ness, equal to the brightness of a, perfectly diffusing surface emitting or reflecting one lumen per square centimeter.
Lambert's cosine law. The luminous intensity of a small element of a perfectly diffusing surface in any direction is proportiomil to the co­sine of the angle between the di­rection and the normal.
Lambrequin. An 'ornamental drapery . or short decorative hanging, pen­ dant from a shelf or from the cas­ing above a window.
Laminar flow. (Aero.) A particular type of streamline flow. The term is usually applied to the flow of a viscous liquid near. solid boundaries, when the flow is not turbulent.