Surveyor Units of Measure

Acre
The (English) acre is a unit of area equal to 43,560 square feet, or 10 square chains, or 160 square poles. It derives from a plowing area that is 4 poles wide and a furlong (40 poles) long. A square mile is 640 acres. The Scottish acre is 1.27 English acres. The Irish acre is 1.6 English acres.

Arpent
Unit of length and area used in France, Louisiana, and Canada. As a unit of length, approximately 191.8 feet (180 old French 'pied', or foot). The (square) arpent is a unit of area, approximately .845 acres, or 36,802 square feet.

Chain
Unit of length usually understood to be Gunter's chain, but possibly variant by locale. See also Rathbone's chain. The name comes from the heavy metal chain of 100 links that was used by surveyors to measure property bounds.

Colpa
Old Irish measure of land equal to that which can support a horse or cow for a year. Approximately an Irish acre of good land.

Compass
One toise.

Cuerda
Traditional unit of area in Puerto Rico. Equal to about .971 acres. Known as the "Spanish acre".

Engineer's Chain
A 100 foot chain containing 100 links of one foot apiece.

Furlong
Unit of length equal to 40 poles (220 yards). Its name derives from "furrow long", the length of a furrow that oxen can plow before they are rested and turned. See Gunter's chain.

Ground
A unit of area equal to 2400 sq. ft., or 220 sq. meters, used in India.

Gunter's Chain
Unit of length equal to 66 feet, or 4 poles. Developed by English polymath Edmund Gunter early in the 1600's, the standard measuring chain revolutionized surveying. Gunter's chain was 22 yards long, one tenth of a furlong, a common unit of length in the old days. An area one chain wide by ten chains long was exactly an acre. In 1595 Queen Elizabeth I had the mile redefined from the old Roman value of 5000 feet to 5280 feet in order for it to be an even number of furlongs. A mile is 80 chains.

Hectare
Metric unit of area equal to 10,000 square meters, or 2.471 acres, or 107,639 square feet.

Hide
A very old English unit of area, a hide was of variable size depending on locale and the quality of the land. It was the amount of land to support a family, and ranged from 60 to 180 acres. After the Norman conquest in 1066 it became standardized at around 120 acres.

Hundred
An administrative area larger than a village and smaller than a county. In England it was 100 hides in size, and the term was used for early settlements in Virginia, Maryland, and Delaware.
Labor
The labor is a unit of area used in Mexico and Texas. In Texas it equals 177.14 acres (or 1 million square varas).

League (legua)
Unit of area used in the southwest U.S., equal to 25 labors, or 4428 acres (Texas), or 4439 acres (California). Also, a unit of length-- approximately three miles.

Link
Unit of length equal to 1/100 chain (7.92 inches).

Morgen
Unit of area equal to about .6309 acres. It was used in Germany, Holland and South Africa, and was derived from the German word Morgen ("morning"). It represented the amount of land that could be plowed in a morning.

Out
An 'out' was ten chains. When counting out long lines, the chain carriers would put a stake at the end of a chain, move the chain and put a stake at the end, and so on until they ran "out" of ten stakes.

Perch
See pole .

Point
A point of the compass. There are four cardinal points (North, South, East, West), and 28 others yielding 32 points of 11.25 degrees each. A survey line's direction could be described as a compass point, as in "NNE" (north northeast). To improve precision, the points would be further subdivided into halves or quarters as necessary, for example, "NE by North, one quarter point North". In some areas, "and by" meant one half point, as in "NE and by North".

Pole
Unit of length and area. Also known as a perch or rod. As a unit of length, equal to 16.5 feet. A mile is 320 poles. As a unit of area, equal to a square with sides one pole long. An acre is 160 square poles. It was common to see an area referred to as "87 acres, 112 poles", meaning 87 and 112/160 acres.

Pueblo
A Spanish grant of less than 1000 acres.

Rancho
A Spanish grant of more than 1000 acres.

Rathbone's Chain
A measuring chain two poles, or 33 feet, in length.

Rod
See pole

Rood
Unit of area usually equal to 1/4 acre.

Toise
Traditional French unit of length equal to 6 old French 'pieds' or feet, or 6.4 English feet.

Vara
Unit of length (the "Spanish yard") used in the U.S. southwest. The vara is used throughout the Spanish speaking world and has values around 33 inches, depending on locale. The legal value in Texas was set to 33 1/3 inches early in the 1900's.

Virgate
An old English unit of area, equal to one quarter of a hide. The amount of land needed to support a person.


Standard Surveying Terms

A Frame
A measuring device built in the shape of an A. The distance between the legs is 6.6 feet (one tenth of a chain. To measure the acreage of a small square parcel, multiply the width and height in "A's" and move the decimal point three places to the left. For example, a square that is 6 A's wide and 4 A's tall is .024 acres.

Aliquot
The description of fractional section ownership used in the U.S. public land states. A parcel is generally identified by its section, township, and range. The aliquot specifies its precise location within the section, for example, the northwest quarter of the southeast quarter.

Auditor's map
was made by the County Surveyor at the request of the auditor for tax purposes. Many were made in the 1800's. Very little field work was done. The map was created bu the use of various documents, piecing together other surveys, a few rough measurements in the field, etc. Generally, not accurate.

Azimuth
The number of degrees from north (or other reference direction) that a line runs, measured clockwise.

Back sight
After measuring from point A to B, reading the heading from B back to A. Various factors can cause the headings to not be exactly the reverse of one another.

Baseline
In the U.S. Public land surveying system, a surveyed east-west (i.e. latitudinal) reference line, often hundreds of miles in length, from which tiers of townships are are surveyed to the north and south. There are approximately two dozen baselines in the lower 48 states. See also meridian.

Bearing
See azimuth. Bearings taken with a compass will be referenced to magnetic north unless otherwise noted.

Benchmark
A survey mark made on a monument having a known location and elevation, serving as a reference point for surveying.

Call
Any feature, landmark, or measurement called out in a survey. For example, "two white oaks next to the creek" is a call. So is "North 3 degrees East 120 poles".

Chain carrier
An assistant to the surveyor, the chain carriers moved the surveying chain from one location to another under the direction of the surveyor. This was a position of some responsibility, and the chain carriers took an oath as "sworn chain carriers" that they would do their job properly.

Chord
The straight line connecting the end points of an arc.

Condition
See Conditional line.

Conditional line
An agreed line between neighbors that has not been surveyed, or which has been surveyed but not yet granted.

Corner
The beginning or end point of any survey line. The term corner does not imply the property was in any way square.

Declination
The difference between magnetic north and geographic (true) north. Surveyors used a compass to determine the direction of survey lines. Compasses point to magnetic north, rather than true north. This declination error is measured in degrees, and can range from a few degrees to ten degrees or more. Surveyors may have been instructed to correct their surveys by a particular declination value. The value of declination at any point on the earth is constantly changing because the location of magnetic north is drifting. More information about historical values of declination is available.

First station
See Point of Beginning

Flag
A bright plastic ribbon tied to a lath stake. Used to mark points along a survey line.

Gore
A thin triangular piece of land, the boundaries of which are defined by surveys of adjacent properties. Loosely, an overlap or gap between properties. See also strip.

Landmark
A survey mark made on a 'permanent' feature of the land such as a tree, pile of stones, etc.

Line Tree
Any tree that is on a property line, specifically one that is also a corner to another property.

Merestone
A stone that marks a boundary. See monument.

Meridian
In the U.S. public land surveying system, a surveyed north-south (i.e. longitudinal) reference line, often hundrends of miles in length, from which ranges are surveyed to the east and west. There are approximately two dozen meridians in the lower 48 states. See also baseline.

Mete
In the context of surveying, a measure, i.e. the direction and distance of a property line.

Metes and Bounds
An ancient surveying system that describes the perimeter of a parcel of land in terms of its bearings and distances and its relationship to natural features and adjacent parcels.
Monument
A permanently placed survey marker such as a stone shaft sunk into the ground.

Open line
A survey line, usually the final one, that is not measured and marked (blazed) by the surveyor but is instead calculated.

Point of Beginning
The starting point of the survey

Point of intersection
The point where two non-parallel lines intersect. More specifically, the point where two tangents to a curved line intersect.

Plat
A drawing of a parcel of land. More specifically, the drawing created by the surveyor that shows the field work, with bearings, distances, etc.

Plot plan
A diagram showing the proposed or existing use of a specific parcel of land.

Plunge
1) Inversion of a transit in order to make measurements that cancel errors in the transit, or to extend a line over an obstacle. 2) The angle a falling line makes with the horizontal.

Protraction
in the rectangular survey system, the representation of a boundary or corner not run, marked, or fixed by the field survey as evidenced by the field notes. For example, a surveyed section might be protracted into lots by someone in the office.

Quarter corner
in the public land surveying system, a point halfway between the corners of a section. A section can be divided into four equal quarters by connecting its quarter corner points. A section's quarter corners are identified by the section line they are located on (north, south, east, west).

Range
In the U.S. public land surveying system, a north-south column of townships, identified as being east or west of a reference longitudinal meridian, for example, Range 3 West. See township.

Riser
a tree branch or other similar object stuck in the ground and flagged to mark a survey point.

Searles Spiral
A surveying technique used by railroad surveyors in the the late 1800s and early 1900s whereby they approximate a spiral by use of multiple curved segments.

Section
In the U.S. public land surveying system, an area one mile square. See aliquot.

Standard Corner
a corner that is on a standard parallel or base line

Strip
A rectangular piece of land adjoining a parcel, created when a resurvey turns up a tiny bit larger than the original survey. The difference is accounted for by temperature or other effects on measuring chains. See also gore.

Tangent line
A line that touches a circle at exactly one point and which makes a right angle with the circle's radius. For example, a circle that fills a square has four tangent points and the square's sides are tangent lines. An arc (curve) in a survey is part of a larger circle. One can construct tangent lines at the end points of the arc.

Tie line
A survey line that connects a point to other surveyed lines.

Tier
In the U.S. public land surveying system, an east-west row of townships identified as being north or south of a latitudinal baseline.

Total station
A survey instrument that combines a theodolite and distance meter.

Township
In the U.S. public land surveying system, an area six miles square, containing 36 sections. The townships are organized in tiers and ranges, identified with respect to a baseline and meridian. For example, Township 13 North Range 6 West describes a township's location.

Traverse
1) any line surveyed across a parcel, 2) a series of such lines connecting a number of points, often used as a base for triangulation.

Trend
the bearing of a line along a falling course.

Trocha
Spanish for 'path'. In the southeast U.S. it is used for a cut or cleared survey line.

Witness Tree
Generally used in the U.S. public land states, this refers to the trees close to a section corner. The surveyor blazed them and noted their position relative to the corner in his notebook. Witness trees are used as evidence for the corner location.

Zenith angle
An angle measured from a vertical reference. Zero degrees is a vertical line pointing up, 90 degrees is horizontal, and 180 degrees is straight down.


Surveyor Slang

Balls
Slang for numeric .00, as in 4-balls (4.00)

Beep
Verb. To use a magnetic detector to look for iron pipe, etc.

Blood
To slowly raise the levels rod in order that the instrument man can read the foot markings.

Boot
To raise the levels rod some number of inches so as to be visible to the instrument man, e.g. "Boot 6!" means "raise it 6 inches."

Blue topping
In road or grading work the surveyor sets stakes and paints their tops blue to represent the required elevation. Graders then work to just cover the blue tops of the stakes.

Box
Data collector.

Bug
To use a magnetic locator to search for an iron pipe.

Bullseye
Zero degrees of inclination.

Burn
See shoot

Burn one
Measure from the one foot mark on the tape rather than from the end of the tape in order to increase the accuracy of the measurement.

Bust
Closure error, i.e. the amount by which the survey fails to perfectly close.

Cap
A metal or plastic cover on the end of a rebar or pipe, typically stamped or printed with the surveyor's license number or other identifier.

Cut line
To clear vegetation for a line of sight between two survey control points.

Double nickel
Slang for .55, as in 6-double nickel (6.55)

Dummy or dummy-end
The base or zero end of a tape or chain, as in "hold dummy at the face of the curb."

Dump
Download data from the data collector.

EDM
Electromagnetic Distance Measurement device, the instrument used by modern surveyors that replaces the use of measurement chains. It determines distance by measuring the time it takes for laser light to reflect off a prism on top of a rod at the target location.

Ginney
A wooden dowel 6-9 inches in length with a sharpened end. Set in the ground to mark survey points.

Glass
The EDM prism.

Gun
Originally, a transit, but potentially any measurement instrument in use, e.g. theodolite, EDM, or Total Station.

Hours
Degrees

Hub and Tack
A 2" by 2" stake that is set in the ground and that contains a nail ("tack") that precisely marks the point being set.

Jigger
Transit (Australia and New Zealand)

Legs
Tripod

Pogo
Prism pole

Pole
Approximate unit of measure (about 0.1 foot) used for stake out, e.g. "Move a pole to the left and drive that hub in"

Punk
See railroad.

Railroad
Slang for eleven, as in 42-railroad (42.11)

Rodman
The person holding the rod with the EDM prism. This person is the modern version of a chain carrier or chain man.

Shoot
Measure distance with an EDM

Spike
Usually a 60 penny nail used to mark survey points in hard ground.

Stob
In the southeast U.S., a wooden stake or post, but in modern surveying, a piece of rebar used to mark a property boundary.

Tie
To locate something with the transit or other measuring device.

Top
Slang for eleven. See railroad.

Trip
Slang for triple digits, as in trip5 means 555, and 43trip7 means 43.777

Turn
The rodman is told to stay in place while the gun or level is moved to a new location.

Wave
To slowly move the levels rod back and forth in order to confirm that a measurement was made when the rod was truly vertical.

Zero
Zero degrees, minutes, and seconds. A perfect zero.


Surveyor Abbreviations

BRL
Building restriction line.

BS
Back sight

BSL
Building setback line.

CIP
Capped iron pin

CL
Center line

Con Mon F
Concrete monument found

DE
Drainage Easement

EBL
East boundary line. Eastbound Lane.

EIP
Existing iron pipe

GRLS
Georgia Registered Land Surveyor

FD
Found

IPF
Iron pipe/pin found

IPS
Iron pipe/pin set

IRF
Iron rod found

IRS
Iron rod set

L.O.D.
Limit of Disturbance. The area to be cleared, graded, etc.

LS
Licensed/Land Surveyor #

MAG

MBS
Minimum building setback

NBL
North boundary line. Northbound Lane.

N/F
Now or formerly

NIP
New iron pin

NMS
No monument set

NPP
Nail in power pole

NTCFP
Nail on top of corner fence post

NTFP
Nail on top of fence post

NTS
Not to scale

PC
Point of curvature. The point at which a straight line begins to curve, i.e. the point of tangency to the curve. See PT.
PCC
Point of compound curvature. The point where curves of different radii meet.

PDE
Public drainage easement

PI
Point of intersection

PK
Point Known, PK nail

PK nail
A concrete nail made by Parker Kaelon, stamped PK, that marks a survey point. See also hub and tack.

PL
Property line

POB
Point of beginning. The starting point of a survey.

POL
Point on line. Used in situations where the end (final) point cannot be seen from the transit. Also used when the final point falls in water.

PRC
Point of reverse curve. The point in an S-type compound curve where two curves of different polarity meet.

PSDE
Private storm drain easement.

PT
Point of tangency. The point at which a curve ends and straight survey line begins. See PC.

RB
Rebar

R/C
Rod and cap, or rebar and cap

RP
Radius point

R/W
Right of way

SBL
South boundary line. Southbound lane.

SC
Standard corner

SCM
Set concrete monument

SMN
Set mag nail

SR
Steel rebar

SRS
Steel rod set (rebar or other steel)

SSE

Sanitary sewer easement

STE
Sight triangle easement

UE
Utility easement

WBL
West boundary line. Westbound lane.

WC
Witness corner


Water Terms for Surveyors

Arroyo
A small steep-walled (usually) dry watercourse with a flat floor. A gulch or gully. Chiefly in the U.S. southwest.

Bank
Edge of a stream.

Bed and banks
For property lines that cross a body of water, this term is used to explicitly refer to the bottom of the water.

Bottom
Land along a river.

Branch
Small stream.

Brook
Small stream.

Creek
Small stream.

Drain
Small dry stream or gully.

Draughts of
(pronounced drafts). See waters of.

Drean
See drain.

Ford
Shallow part of a stream or river where one could cross.

Fork
Meeting point of two streams. "In the fork of" means between two branches.

Gut
A narrow passage between hills. A stream in such a passage. A drain.

Head
The source of a stream.

Headwaters
The smallest streams that combine to make a larger stream.

Kill
(Dutch) Creek.
Lower
Toward the mouth of a stream. Further down along its course. Opposite of upper.

Meander
"with the meanders of the stream" means the survey line follows the twists and turns of the stream.

Mouth
The place where a stream enters another, larger stream.

Narrows
Narrow part of a stream.

River
Large stream.

Run
Small stream.

Shoal
Shallows.

Spring
A pool or other source of water that feeds a stream.

Swale
A low, generally marshy tract of land, either natural or manmade, e.g. for managing water runoff.

Swamp
In the southeastern U.S., a stream, particularly one that has has swampy parts. A marsh.

Thalweg
1. An imaginary line connecting the lowest points of a valley. 2. The line connecting the lowest points of a stream's channel.
3. The surface midline of a channel.
Thread of a creek. A figurative expression used to signify the center line of the main channel of a stream when the flow rate is low.

Upper
Toward the head of a stream. Further up along its course. Opposite of lower.

Vly
(Dutch) Swampy lowland.

Waters ("watters") of
In the drainage of. On the branches of.


Tree Identification for Surveyors

Alder

Ash
has tough, straight-grained wood

Aspen
a type of poplar

Basswood
see linden

Beech
smooth gray bark and small edible nuts

Birch (Burch)

Black gum
see tupelo

Blackjack
a type of small oak

Black Oak

Black Walnut

Box Elder

Box Oak

Buckeye

Buffaloberry

Cedar

Cherry

Chestnut
American chestnut has been virtually destroyed by blight.

Chestnut oak
has leaves resembling a chestnut

Chittamwood
see Wooly Bumelia

Cottonwood

Dogwood

Elder

Elm

Fir

Gambrel Oak
see Oakbrush

Gum
subtypes: black, sweet

Hackberry
has cherry-like fruit

Hawthorn

Hazel

Hemlock

Hickory, hiccory, hickry
has edible nuts and hard wood

Hornbeam
has hard, heavy wood

Ironwood
see hornbeam

Juniper

Larch

Laurel

Lightwood
highly resinous pine, suitable for stakes

Live Oak

Lowerwood
transcription error for sourwood

Maple (Maypole)

Mountain Birch

Oak (Oake)
subtypes: black, box, chestnut, live, pin, post, red, scrub, shrub, Spanish, swamp white, white

Oakbrush
scrub oak prevalent in southern Colorado west of the divide

Pawpaw

Persimmon
has plum-like fruit

Pine

Pin Oak

Pohiccory
see hickory

Ponderosa pine

Poplar (Popular)

Post Oak
wood used for posts

Red Cedar

Red Oak

Sapling (saplin)
young tree

Sassafras
bark used in medicines and beverages

Scrub oak
usually found in dry, rocky soil

Serviceberry (Sarvisberry)

Sour Gum
see Tupelo

Sourwood (sorrel tree)

Spanish Oak

Spruce

Sugar Tree (Sugar Maple)

Sumac (shumac)

Swamp white oak
heavy, hard wood used in shipbuilding, furniture, etc.

Sweet gum
hard reddish brown wood used for furniture

Sycamore

Tamarack
an American larch having reddish brown bark

Tamarisk

small shrub found in the southwest

Tupelo

Walnut
black

White oak

Wooly Bumelia
leaves resemble a live oak with a fine fur-like fuzz on the underside.

Yew
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