The Tool Used to Draw Circles and Arcs
A axle compass and a regular compass
A compass with an extension accompaniment for larger circles
A bow compass capable of drawing the smallest possible circles
A compass, more accurately known every bit a pair of compasses, is a technical drawing musical instrument that can exist used for inscribing circles or arcs. As dividers, it can also be used as a tool to step out distances, in particular, on maps. Compasses can be used for mathematics, drafting, navigation and other purposes.
Prior to computerization, compasses and other tools for manual drafting were frequently packaged every bit a fix[1] with interchangeable parts. By the mid-twentieth century, circumvolve templates supplemented the use of compasses.[ commendation needed ] Today those facilities are more often provided by reckoner-aided design programs, then the physical tools serve mainly a didactic purpose in didactics geometry, technical drawing, etc.
Construction and parts [edit]
Compasses are usually made of metallic or plastic, and consist of two "legs" connected by a hinge which can exist adjusted to let changing of the radius of the circle fatigued. Typically one leg has a fasten at its finish for anchoring, and the other leg holds a drawing tool, such equally a pencil, a short length of but pencil lead or sometimes a pen.
Handle [edit]
The handle, a small knurled rod above the hinge, is usually about one-half an inch long. Users can grip it between their pointer finger and pollex.
Legs [edit]
At that place are two types of leg in a pair of compasses: the straight or the steady leg and the adjustable one. Each has a separate purpose; the steady leg serves equally the basis or support for the needle point, while the adjustable leg can be altered in order to draw different sizes of circles.
Hinge [edit]
The screw through the hinge holds the ii legs in position. The hinge tin be adjusted, depending on desired stiffness; the tighter the swivel-spiral, the more than accurate the compass's performance. The improve quality compass, made of plated metal, is able to be finely adapted via a minor, serrated wheel usually set up between the legs (see the "using a compass" animation shown above) and it has a (dangerously powerful) jump encompassing the swivel. This sort of compass is oft known as a "pair of Spring-Bow Compasses".
Needle betoken [edit]
The needle point is located on the steady leg, and serves as the eye betoken of the circumvolve that is about to be fatigued.
Pencil lead [edit]
The pencil pb draws the circle on a particular newspaper or cloth. Alternatively, an ink nib or zipper with a technical pen may be used. The improve quality compass, made of metal, has its piece of pencil lead especially sharpened to a "chisel edge" shape, rather than to a point.
Adjusting nut [edit]
This holds the pencil lead or pen in place.
Uses [edit]
Circles can be made by pushing i leg of the compasses into the paper with the spike, putting the pencil on the paper, and moving the pencil around while keeping the legs at the same bending. Some people who notice this action difficult ofttimes hold the compasses still and motion the paper round instead. The radius of the intended circle can be changed by adjusting the initial angle betwixt the two legs.
Distances tin can be measured on a map using compasses with 2 spikes, also chosen a dividing compass (or but "dividers"). The hinge is set in such a way that the distance between the spikes on the map represents a certain altitude in reality, and by measuring how many times the compasses fit between two points on the map the distance betwixt those points can be calculated.
Compasses and straightedge [edit]
Compasses-and-straightedge constructions are used to illustrate principles of plane geometry. Although a existent pair of compasses is used to draft visible illustrations, the platonic compass used in proofs is an abstruse creator of perfect circles. The most rigorous definition of this abstract tool is the "collapsing compass"; having drawn a circle from a given point with a given radius, it disappears; information technology cannot simply be moved to another signal and used to draw another circumvolve of equal radius (unlike a real pair of compasses). Euclid showed in his second proposition (Book I of the Elements) that such a collapsing compass could be used to transfer a distance, proving that a collapsing compass could do annihilation a real compass tin do.
Variants [edit]
A axle compass is an musical instrument, with a wooden or brass beam and sliding sockets, cursors or trammels, for drawing and dividing circles larger than those made by a regular pair of compasses.[two]
Scribe-compasses [3] is an instrument used by carpenters and other tradesmen. Some compasses can exist used to describe circles, bisect angles and, in this case, to trace a line. It is the compass in the most simple form. Both branches are crimped metallic. One branch has a pencil sleeve while the other co-operative is crimped with a fine point protruding from the end. A fly nut on the hinge serves two purposes: first it tightens the pencil and secondly it locks in the desired distance when the fly nut is turned clockwise.
Loose leg wing dividers [iv] are made of all forged steel. The pencil holder, thumb screws, brass pivot and branches are all well built. They are used for scribing circles and stepping off repetitive measurements[5] with some accuracy.
A proportional compass, also known as a military machine compass or sector, was an instrument used for calculation from the end of the sixteenth century until the nineteenth century. It consists of 2 rulers of equal length joined by a swivel. Different types of scales are inscribed on the rulers that allow for mathematical calculation.
A reduction compass is used to reduce or enlarge patterns while conserving angles.
As a symbol [edit]
A computer drawn compass, used to symbolize precise designing of applications.
A pair of compasses is frequently used as a symbol of precision and discernment. As such it finds a place in logos and symbols such as the Freemasons' Square and Compasses and in diverse computer icons. English poet John Donne used the compass as a conceit in "A Valediction: Forbidding Mourning" (1611).
-
Compass for tracing a line.
-
Flat branch, pivot wing nut, pencil sleeve co-operative of the scribe-compass.
-
half dozen inch (15 cm) dividers made from forged steel.
-
I type of sector.
-
The compass is a Masonic symbol that appears on jewellery such as this pendant.
Meet also [edit]
- Dividers
- Circumvolve
- Geometrography
- Masonic Square and Compasses
- Technical drawing tools
References [edit]
- ^ a current vendor's product
- ^
This article incorporates text from a publication now in the public domain:Chambers, Ephraim, ed. (1728). "Beam-Compasses". Cyclopædia, or an Universal Dictionary of Arts and Sciences (1st ed.). James and John Knapton, et al. - ^ Fine Woodworking, Build a Fireplace Mantel, Mario Rodriquez, pgs. 73, 75, The Taunton Press, No. 184, June 2006
- ^ The Carpenter'due south Manifesto, Jeffrey Ehrlich & Marc Mannheimer, Holt, Rhinehart & Winston, pg. 64, 1977
- ^ Fine Woodworking, Laying out dovetails, Chris Gochnour, pg. 31, The Taunton Press, No. 190, April 2007
External links [edit]
- Beam or trammel compass (variant form)
Source: https://en.wikipedia.org/wiki/Compass_%28drawing_tool%29
0 Response to "The Tool Used to Draw Circles and Arcs"
Post a Comment