- azimuth: The angle of horizontal deviation, measured clockwise, of a bearing from a standard direction, as from north or south.
- abut: To touch at the end or boundary line; to be continuous.
- boundary-stone: Tablet, post, etc., erected to mark the extent of an estate, parish, or other boundary.
- magnetic north: North as indicated by the north-seeking pole of the magnetic needle in a compass.
- true north: The direction of the north pole from a given point.
- instrument station: A precisely located reference point over which a surveying instrument is centered.
- spot elevation: The elevation of a certain point relative to a specified datum.
- bearing: The support, or surface of same, upon which a structural load rests. 2. The length of bearing given a beam or joist upon a wall. 3. A horizontal direction expressed in degrees east or west of a true or magnetic north or south direction.
- level: Surveyor’s level, an instrument for measuring heights of land or other objects above a plane of reference. 2. An instrument used by carpenters or masons for establishing horizontality or verticality in a member. 3. A device for determining true horizontal or vertical directions by the centering of a bubble in a slightly bowed glass tube filled with alcohol or ether. Also called spirit level.
- surveyor’s chain: A distance-measuring device consisting of 100 metal links and a total length of 66 ft. (20 m).
- theodolite: A precision instrument having a telescopic sight for establishing horizontal and sometimes vertical angles.
- transit: An instrument for measuring angles on a horizontal plane, used in surveying.
- plat: To make a plan of land divisions, streets, etc. 2. A plan or map of land in a city, town, section, or subdivision, indicating the location and boundaries of individual properties.
- Gunter’s chain: A measure by surveyors, equivalent to 66 feet.
- rod: A piece or strip of wood, such as could be cut out of a plank; that is to say, about 2 inches square; as used by carpenters for setting out their work… 2. A unit of length equal to 5 1/2 yards 16 1/2 feet, and equivalent to 5.029 meters. 3. A straight pole or bar, conspicuously marked with graduations, and used in measuring the vertical distance between a point on the ground and the line of sight of a surveyor’s level. Also called leveling rod, stadia rod.
- artificial horizon: A level, as a surface of mercury.
- alignment: An adjustment in a straight line. 2. The theoretical, definitive lines that establish the position of construction (such as a building) or the shape of an individual element (such as a curved or straight beam). 3. In highway and other surveys, the ground plan depicting direction of the route as distinguished from a profile, which shows the vertical element. 4. In prehistoric building, formal alleys of standing stones, as at Carnac in France.
- baseline: The principal east-west reference line for an area in the rectangular system of survey. 2. A line of known length and position from which points or other lines may be established, as a corner of a building structure or a property line.
- building line: Line beyond which a building may not encroach: it might, for instance, define the frontage of facades in a street.
- correction line: An east-west reference line located at 24-mile intervals to the north and south of a baseline in the rectangular system of survey, established to correct for the convergence of meridians and equalize east-west distances.
- guide meridian: In the rectangular system of survey, a north-south reference line located between correction lines at 24-mile intervals to the east and west of principal meridians.
- principal meridian: In the rectangular system of survey, a north-south reference line established at a substantial landmark for a large area of land.
- range line: In the rectangular system of survey, a north-south reference line located at 6-mile intervals between guide meridians.
- butts and bounds: A legal term for the boundary lines of a parcel of land as used in deeds and titles.
- datum: An assumed, given, or otherwise determined fact or proposition from which conclusions may be drawn or decisions made. 2. Any level surface, line, or point used as a reference from which elevations are measured.
- datum level: Also see datum level.
- datum line: Also see datum point.
- datum point: Also see datum point.
- differential leveling: A procedure for determining the difference in elevation between two points by means of a level or transit and a rod.
- leveling: A procedure for determining the difference in elevation between two points by means of a level or transit and a rod. Also called differential leveling.
- levelling: See surveying.
- metes and bounds: A means of describing the location of parcels of land by defining boundaries in terms of directions and distances from one or more specified points of reference.
- metes-and-bounds survey: A system of land survey in which the course and length of each boundary line of a parcel of land are called out starting at a known reference point and working around the periphery of the plat until returning to the place of beginning.
- stadia rod: A straight pole or bar, conspicuously marked with graduations, and used in measuring the vertical distance between a point on the ground and the line of sight of a surveyor’s level.
- stake out: To mark, with stakes driven into the ground, the location of a proposed structure.
- township: A unit of land area in the rectangular system of survey, approximately 6 sq. mi. (93.2 sq. km) containing 36 sections.
- triangulation: Any construction based on a continuous series of triangles to give stability. 2. A trigonometric method for determining the position of a point by taking bearings from the end points of a baseline of known or measurable length.
- trilateration: A method for determining the relative positions of three or more points by treating these points as vertices of a triangle or triangles of which the sides and angles can be measured.
- bench mark: A datum point from which differences in level are reckoned. 2. A marked point of known or assumed elevation, usually on a permanent object, from which other elevations may be established.
- place of beginning: The starting point for a metes-and-bounds survey.
- set-up: A precisely located reference point over which a surveying instrument is centered.
- turning point: A point temporarily located and marked in order to establish the elevation or position of a surveying instrument at a new station.
- cadastral survey: A survey showing boundaries and property lines, usually made to create land units suitable for transfer of title.
- land survey: A survey made to establish the length and bearing of boundary lines and the area of the tract bounded by these lines.
- legal description: A written description of the location and boundaries of a specific parcel of land, based on a metes-and-bounds survey or a rectangular system of survey, or made with reference to a recorded plat.
- plane survey: A survey in which curvature of the earth’s surface is ignored, and all distances and horizontal angles are assumed to be projected onto a horizontal plane.
- survey: A plan, map, or plotting, made from measurements and angles taken, and lines run, as described under Surveying; also the whole operation of surveying a piece of ground or the like, and recording the results in such a map. 2. To determine the exact form, boundaries, extent, and position of a tract of land by linear and angular measurements and the application of the principles of geometry and trigonometry.
- survey plat: A legal document describing the location, boundaries, and dimensions of a tract or parcel of land, including zoning and planning commission approvals, easements and restrictions, and, for a subdivision, the dividing lines of street blocks, and lots, and the numbering and dimensions of each lot.
- government system: A system of land survey based on a modified grid of north-south principal meridians and east-west baselines.
- rectangular system: A system of land survey based on a modified grid of north-south principal meridians and east-west baselines. Also called government system.
- alidade: The entire upper part of a transit or theodolite, including the telescope, its supports, spirit level, horizontal circle, leveling devices, and the spindle.
- engineer’s chain: A measure used by engineers, equivalent to one hundred feet.
- horizontal circle: A circular plate, graduated in degrees, minutes, and seconds, and fixed to the base of a transit for measuring horizontal angles.
- leveling rod: A straight pole or bar, conspicuously marked with graduations, and used in measuring the vertical distance between a point on the ground and the line of sight of a surveyor’s level.
- optical plummet: A device for centering a transit or theodolite over a reference point, used in place of a plumb bob in a strong wind.
- spirit level: A device for determining true horizontal or vertical directions by the centering of a bubble in a slightly bowed glass tube filled with alcohol or ether.
- target: A red and white disk on a leveling rod that facilitates the sighting and reading of the rod.
Also see Architecture index.