Abstract: A tool for laying out a pattern of a measured size and orienting the pattern with respect to an exterior point of reference is disclosed. A cord having a plurality of anchoring points spaced along its length is arrayed to form the pattern. A direction finding device orients the pattern formed by the cord to a point of reference exterior to the pattern. Anchoring devices anchor each anchoring point of the cord to a surface so that the cord is held to the surface in the shape of the pattern. The cord is attached to a spool which stows the cord, anchoring devices, and direction finding device when not deployed.

Abstract: As equipment has a transducer (G) that receives signals from a number of objects with unknown positions and senses the directions from the transducer to the objects. The directions of the sight lines to the objects are sensed in at least two separate transducer locations. The transducer signals are supplied to calculator (CU) which calculates the positions of the objects.

Abstract: A chalk line dispenser holder system is provided including at least one chalk line dispenser for selectively dispensing a chalk line from a periphery of the dispenser. Also included is a structure connected to an end of the chalk line for resting on a recipient surface onto which chalk is to be applied. A weight of the structure precludes the movement of the end of the chalk line.

Abstract: The device comprises a pipe (1), in which a shaft (20) of a marking component (2) can be moved. The pipe (1) has a soil anchor (4) at the bottom. The component (2) has a head (21) at the top and can be lifted from a lowered position, in which the head (21) lies next to the top face (14) of the pipe (1) into the lifted position shown against the force of a spring (3). In the lifted position, the component (2) can be stopped by means of a bayonet lock. The device is inserted into the ground vertically at a measuring, e.g., on a soccer field, such that in the lowered position, the top (25) of the head (21) is flush with the ground surface. If the markings on the field need to be renewed, the corresponding components (2) are lifted and stopped. A cord is stretched between two components (2), along which cord a straight line can be marked, or a circle can be drawn with a cord around one of the components (2). The marking of the field can thus be rationalized and expensive re-measuring can be avoided.

Abstract: A template system is provided for laying out the location of telecommunication switching cabinets in a switching center. The template system includes a plurality of fixture templates and a plurality of connector pieces for joining the fixture templates to one another. Each fixture template includes pre-formed marking holes and pre-formed marking slots to mark the layout of the cabinet. The marking holes are used to mark the location of mounting holes in the floor. Marking slots are used to mark the location of access openings for wiring in suspended floor systems. The connector pieces interlock with the fixture templates so that the fixture templates are always spaced a predetermined distance from one another. The interlocking fixture templates and connector pieces minimize the reliance on measurements thereby reducing the number of errors likely to occur when laying out the cabinets.

Abstract: An aid for navigation, positioning and/or orientation, said aid comprising a transparent plate (1) comprising a straight first edge (5); a straight second edge (7) which is at right angles against the first edge, a longitude line (4) which has been drawn on the plate (1) to parallel the first edge (5), a latitude line (6) which has been drawn on the plate (1) to parallel the second edge (7), and a position index point (3) which is located at the intersection of the longitude line and the latitude line, a latitude pointer (10) which is connected in the vicinity of the first edge (5) to be movable in direction paralleling the first edge, and longitude pointer (11) which is connected in the vicinity of the second edge (7) to be movable in direction paralleling the second edge.

Abstract: This invention relates to a quilt graphing system that enables a quilter to custom design quilts and appliques. The quilt designing system includes at least one transparent quilt graphing grid and a template. The grid has a plurality of uniform squares with dimensional markings (dots and dashes) on all four sides of each square in the grid. The dimensional markings divide each side of the square into thirds and quarters. So marked, the quilt graphing grid enables the quilt maker to graph in straight lines, extending between the dimensional markings, artwork beneath the transparent grit or artwork graphed directly on the grid. The template is specially designed for use by the quilt maker in marking each square of fabric to correspond with the shape of a specific portion of the selected design, and for cutting the squares of fabric with seams for piecing together the fabric squares to form the selected design.

Abstract: A method of staking out a point on the ground using a satellite positioning system comprises the following steps: two reference points near a target point are marked on the ground and the positioning system antenna is located on each of the two points to determine their coordinates, the position of the target point relative to the two reference points is determined from these coordinates, the point corresponding to this relative position is marked on the ground, and the staking out is done at this point. The device for implementing the method includes arrangements for marking the two reference points and the target point on the ground.

Abstract: A dimple configuration for the surface of a golf ball is provided by selecting a fixed number of dimples, placing said dimples on a model of the ball in random, helter-skelter locations on one selected section without regard to the other dimples present, and identifying each dimple and the adjacent dimples which overlap it. For each dimple so identified, the aggregate component of overlap in the longitudinal and latitudinal directions is determined, the center of each dimple is relocated so as to minimize overlap, and the steps of identifying, determining, and relocating are repeated for each dimple until the aggregate overlap is reduced to a predetermined amount. The resultant ball provides a random dimple configuration which has no repeating patterns within the sections.

Abstract: An alignment mechanism and method for using the same are disclosed in which the alignment mechanism includes a sheet of translucent (including transparent) material with a plurality of horizontal and vertical intersecting traces positioned to form a grid. In a preferred embodiment, the sheet of translucent material is made of static cling vinyl to allow the sheet to hold itself to glass and other smooth surfaces. The sheet of material can also include centered X and Y axes to enable the user to determine the center of the sheet--thereby allowing the user to appropriately position art works relative to one another without relying on unaided perception.

Abstract: A template for facilitating marking of entry holes in a surface for passage therethrough of conduit has a flat portion formed of semi-rigid material and two flat sides. The flat portion has a central opening and a plurality of markings on one side. The markings are parallel to a section of the perimeter and spaced inwardly at graduated distances therefrom. A plurality of slots are formed through the flat portion, spaced apart and parallel to one another, substantially coextensively with each corresponding one of the plurality of markings, to thereby permit a user of the template to make a mark through one of the slots to indicate an outer edge of a hole of a preselected size to be formed using the template.

Abstract: A device for defining the profile of a basketball foul lane and key on a surface such as asphalt or concrete. The device is comprised of a plurality of panels wherein each panel has opposing side walls which define a section of the profile therebetween. Connecting ribs are disposed between the side walls for the purpose of connecting the side walls. The plurality of panels is arrangeable so that the sections of the profile align to form the profile of a basketball foul lane and key. The device may be conveniently supplied and sold as an apparatus which includes the device, tape to temporarily attach the device to the solid surface, paint to paint the profile exposed on the surface by the device and a plumb bob to properly align the device on the surface.

Abstract: A real estate electro tape is provided that measures the length of an interior or exterior wall or other similar structure using optical means. A sonic tape is used to measure the perpendicular distance from the device to the interior or exterior wall. Two steerable lasers are then used to determine the angles between the perpendicular and the beams aimed at the wall edges. An algorithm is applied to the angular and perpendicular distance data to obtain the length of the wall. A microprocessor performs the calculations, the results of which are displayed on an electro optical display.

Abstract: A reel dedicated to the layout of a baseball diamond includes a tape with an inner end reeled onto a reel body and an outer end attached to the reel body to form a loop of the tape. The loop has a length 2x+.sqroot.2x and has a first base marking at a distance x from the outer end, a second base marking at a distance 2x from the outer end, a third base marking at a distance x+.sqroot.2x from the outer end and a pitcher's plate marking at a distance of y from the inner end. x is equal to the required distance between bases. y is equal to the distance of the pitcher's plate from home base. The loop is pulled out into a first triangle from first base to second base and back to home plate and then in a second triangle from home plate to first base and to third base to accurately lay out the positions of pegs.

Abstract: A plate structure is arranged for positioning medially of an underlying fabric pattern permitting severing of an associated fabric web relative to the fabric pattern to provide for the symmetrical removal of the pattern relative to the underlying fabric web.

Abstract: An apparatus for use in the design of a package including a portion having therein a recessed area adapted to house an article, the apparatus comprising: a model of the package portion, a model of the article, the article model being locatable on the package model, and structure for identifying, in two dimensions, the position and orientation of the article model on the package model when the article model is located on the package model.

Abstract: A disposable paper template for accurately marking building panels to facilitate cutouts for windows, doors and other objects in a building wall. The template is formed from a thin transparent paper and is sized to conform to the panel for which it is to be used. The template carries thereon level lines and measuring scales to facilitate alignment and use.

Abstract: A modular marking system for permanently marking the playing field on an athletic field with removable upright visible markers containing a variable diameter spring means for attaching an above ground, upright visible marker to a ground anchor. The variable diameter spring means comprises heavy gauge coiled steel having a large diameter coil section disposed within the ground anchor and a small diameter coil section secured within the upright visible marker, where the intermediate diameter reduction area is approximate to ground level to facilitate bending at ground level upon impact from any direction. The ground anchors permanently mark critical intersecting points of playing field lines, where the ground anchors can be used for aligning and visible marking playing field lines and subsequently for supporting the upright visible markers. The modular marking system is particularly useful for permanently marking different playing fields on the sme athletic field.

Abstract: A layout for a static structure, such as a building or the like, is defined using a plurality of triangles and a plurality of tethering cables. The layout is effected by measuring from a property line for a starting point and for a length of a base line. The triangles and tethering cables are located and connected to define at least one angle, and further angles and lines are measured from this first angle.

Abstract: A marking system is disclosed that enables a user to lay out a foundation/perimeter for a structure without requiring the use of measuring instruments and/or complex procedures. The system includes six wire-like premeasured members that are releasably attached to specially designed corner members. The system is laid out with four of the wire-like members enclosing a square or rectangular area with their ends attached to the corner members. The remaining two wire-like members diagonally cross the enclosed area and each is attached at its ends to opposite corner members. When the diagonals intersect at their midpoints, the user is assured that the corners form right angles. Each of the diagonally placed members preferably includes a marking band at its midpoint to facilitate the locating of the midpoints by a user.

Abstract: A method for erecting tent structures is provided and is especially useful for large are tensioned tent structures that include a flexible covering having a vertex portion and spaced corner portions and which has a selected geometrical shape in the erect position. The broad method of the present invention thus contemplates the broad steps of providing such a flexible covering having a vertex and corner portions, securing the corner portions to the support surface, positioning a pole assembly in an upright position between the support surface and the vertex portion and forcibly expanding the pole assembly to tension the flexible covering in a taut condition. Preferably, the tent structure has a base perimeter in the shape of a regular polygon with the structure shaped generally as a pyramid. The covering is formed of fabric panels cut to enhance the effect of tensioning forces. The invention also contemplates tent erection methodology for tent structures having a plurality of center pole assemblies.

Abstract: Templates for use in the laying out selected features of basketball court with relation to the location of the backboard including a flexible planar elongate sheet of material having a index to locate the backboard in relation to the template with slits provided within the template to outline aspects of a basketball court with relation to the index provided by the backboard and including the freethrow lane, freethrow circle freethrow line as well as other features of a basketball court such as the three point line, baseline, and out of bounds.

Abstract: A template is provided for marking a picture mat blank in preparation for subsequent cutting. The template is comprised of two planar arms, a mat-opening design cut into the re-entrant corner of the arms, and graduation lines on the arms for measuring the widths of the mat borders. The template is placed in position on the back of a mat blank so that the arms are parallel with the edges of the mat blank and the edges of the mat blank line up with the appropriate graduation lines for the border widths desired. The inside edge of the template is then traced onto the mat blank with a pencil. Layout marks which show users of mat cutting machines where to start and stop cutting may also be traced. In addition, mat-opening designs incorporating cut out circles and ovals in the mat blank may be laid out using the template.

Abstract: A method is disclosed by which an article of art comprising a mosaic-like pictorial design may be made. The pictorial design comprises an arrangement of a plurality of flat, colored pieces of material, with each piece having the configuration of a square, a triangle or a rectangle. The pieces are pictorially arranged by visually following a separate, mosaic-like pattern of numerically color-coded shapes which lie on a grid pattern of intersecting transverse and longitudinal lines which form rows of equal-sized squares and wherein the coded shapes are square, with the size of a grid square, triangular, and rectangular; the triangular shape formed by diagonally bisecting a square, and each rectangular shape by bisecting a square with a line parallel to a transverse or longitudinal line.

Abstract: A draughting apparatus 10 comprising a plurality of substantially planar symbols elements 30 having raised outlines 50 for depicting predetermined symbols 32, a support panel means 12, 16, for supporting the symbols elements 30 in a generally planar layout, said symbols elements 30 being provided with symbol element locating means 34, 16, and symbol transfer means comprising a self-duplicating set of sheets 36 of draughting material having at least two sheets 36, and a pressure transfer means 24, said at least two sheets 36, being disposable between said raised outlines 50 of said symbols elements 30 and said pressure transfer means 24 so that pressure applied by said pressure transfer means 24 causes the outline of said symbols 32 to be transferred to at least one of said two sheets 36 to create an image of said symbols outlines thereon.

Abstract: The present invention relates to a method and apparatus for allowing the accurate calculation of the minimum number of linear feet of carpet which must be cut from a standard width roll and delivered to an installation site to completely, properly and efficiently cover the floor at the installation site. The present invention provides a length of measurement tape which is scaled in width to the width of a standard roll of carpet. The measurement tape is perforated at increments along its length and width, and includes indicators of carpet grain direction and pattern repetition intervals along its length and/or width.

Abstract: A contract estimating system includes a digitizer ruler divided into a plurality of equally spaced increments. The ruler generates an output signal representing the distance along the ruler at a point touched by a hand held probe. A digitizer board carries a menu thereon including a plurality of indicia such as words, pictures and numbers representing different component parts and sizes and scale factors and generates an output signal corresponding to one of the indicia when touched by the probe. A computer automatically counts the number of each size component part and calculates the total length of pipes and similar components measured by the ruler. The results calculated by the computer can be displayed on a CRT and/or printed on a printer.

Abstract: A bar code ruler is divided into a plurality of equally spaced increments each of which is marked by a machine readable bar code number. The ruler includes a plurality of recesses along the length thereof which cooperate with a spring biased ball carried by a slide member, the ball and recesses functioning as a detent to temporarily maintain the slide member in any desired position on the ruler. A hand held bar code reader is used to scan the bar code number on the ruler next to the slide with the edge of the slide functioning as a guide. A menu is also provided which includes a plurality of bar codes representing different component parts and sizes and a plurality of scale factors. The bar code reader can read the codes on the menu and on the ruler and feeds the information to a computer which counts the number of each size component part and which calculates the total length of pipes and similar components measured by the ruler.

Abstract: A column marker (10) to be used for marking columns on a book layout sheet (42) comprises an elongated ruler member (12) defining a straightedge (14) and a display surface (16) having unique column-marking indicia thereon. The unique column-marking indicia includes a plurality of sets (18A-G) of three side-to-side adjacent elongated bars (20A, 22A; and 24A; 20R; 22B, and 24B, etc.). The bars are parallel to the straightedge and many of the bars in each set are longer than other bars in the set. The longer bars are positioned further from the straightedge than the shorter bars. First ends (26) of the bars are aligned, while perpendicular tails (28 and 30) at second ends of the longer bars extend to the straightedge beyond ends of the shorter bars (32A-32G).

Abstract: An image layout arrangement suitable for transposing small template located images into large work surface located images with any required degree of image resolution and detail, using simple, low-cost tools. An exemplary layout of aircraft images to a runway surface for use in enhancing air base survivability is included and employs point-by-point image transposition according to a plurality of point locating arrangements.

Abstract: A right-angle index device comprising two unextensible tapes having hook means at one free end, a first mechanism for withdrawing said both tapes by the same length under controlled conditions, a second mechanism for stopping said first mechanism to fix the length of said both tapes at the desired value, a take-up mechanism for rolling up said both tapes through said first and second mechanisms, to which the other ends of said both tapes are fixed, and casing means for accommodating therein said first and second mechanisms and said take-up mechanism and allowing said both tapes to be rolled around said take-up mechanism for withdrawal.

Abstract: Wooden structures are assembled from a plurality of wooden elements with interposed metallic connectors, by assembling the wooden elements on a work table provided with a rectangular grid. The image of the structure to be assembled, with a superposed grid corresponding to the grid on the table, is projected on the table until the respective grids register with each other. Then the wooden elements are assembled on the picture; and as the corners of the grid on the table are tapped holes, retainers can be used to hold the assembled elements in place. The table with thus-assembled wooden elements is then run through an endless belt press having superposed convergent runs, whereby the metallic connectors are sunk into the wooden elements to complete assembly of the structure, after which the completed structures are removed from the tables onto rollers with interspersed lifting arms that swing vertically about an axis parallel to the direction of movement of the tables.

Abstract: A duplicating stencil has its heading strip in the form of two separate regions separated by a perforation line.The holes on one region have a different arrangement from those on the other regions, so that tearing along the perforation line allows one region to be separated from the rest of the stencil and to leave the holes of the remaining region as the effective mounting holes.A single image field and a single top edge guide line apply for all of the heading strip regions.

Abstract: A novel electrical interconnection system is described. The system includes a novel multiple-bussed matrix board and associated hardware and assembly tools for use therewith. The matrix board includes a plurality of plated-through holes arranged in a coordinate system of rows spaced 0.100 inches on center, measured from aperture-to-aperture. Selected apertures are electrically connected to selected bus bars on one or the other side of the board.

Abstract: A tool for use by carpenters and the like for conveniently establishing a reference line on a working surface at a predetermined angular disposition from an established base line on said surface. The tool includes an elongated member from which angle lines or cords are each adapted to extend a predetermined distance such that the intersecting terminal ends of such cords in combination with the member, form a triangle having sides of known length. Inasmuch as the length of the triangle's sides are known, the angles included thereby are also known such that a chalked line connected to the member may be utilized to establish a reference line at a known angular disposition to the member. The tool has particular utility when it is desired to establish the angular relationship of a wall to be built with respect to an already existing wall.

Abstract: Apparatus for mapping the outline of a surface area, such as a golf green, including a board having depending legs for placement on the green and a centrally mounted pivot peg extending upwardly from the top of the board. A sheet of paper is attached to the top of the board and typically surrounds the pivot peg. A dual segment measuring element includes an inner, rigid, proportional measuring segment and an outer, flexible, full-scale measuring segment. The inner measuring segment has a pivot hole for engagement around the pivot peg. The inner and outer measuring segments both have their respective zero-points of their scales coincident with the pivot hole. Full-scale measurements are transferred to the paper at corresponding points along the inner, proportional measuring segment.

Abstract: A signmaker's jig assembly incorporates a signblank-supporting worktable, a setting bar movable over the signblank for guiding the alignment of a line of letters to be installed on the signblank, a letter staging zone incorporating a letter aligning staging bar, a centering guide, and a manually movable adhesive transfer bar co-acting with the staging bar for seizing the staged line of letters en bloc, transferring them to the signblank, and installing them thereon. Different embodiments incorporate different features facilitating stripping each line of letters from the staging zone.

Abstract: A device useful for setting up a baseball diamond which comprises a central prong and two secondary prongs, which are positioned in such a manner so as to facilitate the positioning of first, second, and third bases as well as the pitcher's rubber on a baseball diamond.

Abstract: A thermally insulative buoyant swimming pool cover floats on the surface of the pool for covering the pool and for retaining the heat within the pool. Sinking means, such as weights or a mechanical pull-down structure, may be secured to the pool cover along certain predetermined action lines such as fold lines. In one embodiment, an inflatable and deflatable bladder is coupled to the weights. The bladder is dimensioned relative to the weights such that when inflated it overcomes the negative buoyancy of the weights to retain the pool cover in the fully covered position. However, when the bladder is deflated, the weights ovecome the positive buoyancy of the cover along the certain fold lines causing the cover to be at least partially pulled below the surface of the pool and folded while at the same time being retracted against one of the side walls of the pool. Pool water is circulated over or through channels of the pool cover to provide solar heating.

Abstract: A tractor-trailer calculator includes several tractor-trailer indicia portions slidably supported on an elongated support structure at positions to simulate a tractor-trailer vehicle. The indicia portions include a tractor cab portion, a tractor tandem axle portion, a tractor fifth wheel and trailer king pin portion, front and rear trailer portions and a trailer tandem axle portion. Each portion is slidably supported on the support structure in overlapping relation to at least one adjacent portion whereby the overall length of the simulated vehicle and the relative positions of the overlapping portions may be varied to conform to predetermined length requirements for a tractor-trailer vehicle. Measurement devices are associated with the pairs of overlapping indicia portions to indicate their relative positions. Another measurement device is adjustably and slidably supported on the support structure adjacent the indicia portions for measuring various lengths of the simulated tractor-trailer vehicle.

Abstract: An apparatus is disclosed for manufacturing parts for cylindrical vessels comprising a supporting structure having adjustable bearing and stop elements for positioning prefabricated and shaped segments.

Abstract: Apparatus for determining whether an intermediate terrain feature blocks the line of sight between a pair of spaced terrain points, comprising a linearly extending base, at least three spaced posts extending perpendicularly to the base and having cursors on them, the distances between the posts being selectively adjustable. In one embodiment, the base is of three telescopic sections, with a post mounted on each of the sections. In another embodiment, the base is fixed and has three sliders, on each of which a post is mounted. The posts are pivotally mounted on the base, so as to be stored substantially parallel to the base.

Abstract: A device, for selecting sets of rolls for twenty-high rolling mill, comprising a flat board, whereupon eccentric disks are mounted in full conformity with the positioning of the backup rolls of a rolling mill, dimensions of said disks corresponding to the dimensions of the backup rolls of the rolling mill. Secured on the board is a vertical guide member, for displacement of disks corresponding to the working roll and second intermediate idle roll, and a horizontal bar corresponding to the passline of rolling mill, with respect to which the position of the working roll is determined. In addition, there are other disks which are installed on the board in compliance with the positioning in the rolling mill of the first intermediate and second intermediate drive rolls, thus forming a two-dimensional model of the roll arrangement in the rolling mill.

Abstract: Apparatus for illustrating the structural and distance relationship between the subject to be photographed in a studio and the photographic equipment used. The apparatus includes a horizontal board representing the floor of the studio. A predetermined pattern of holes or apertures are located in the board beginning with a center hole and continuing with a plurality of holes forming concentric circles therearound. The distance from the center hole to each concentric circle of holes is scaled. Models representing the subject and the photographic equipment comprise a head portion to identify the model and a graduated support piece. The graduations on each support piece correspond to the scaled distances from the center hole to each of the concentric circles of holes. The models are placed at different distances and angular positions from the center hole and inserted in the concentric circle holes so that the portion remaining above the horizontal board is representative of the height of the equipment.

Abstract: A method for producing sculptures which have a thin-walled outer metal shell and an internal soft core made of plaster, for example. A mold of the sculpture to be fabricated is constructed smaller by the thickness of the metallic outer shell. A substance which can withstand high temperatures when coming into contact with molten metal, such as plaster, is then poured into the mold. After the plaster cast is removed from the mold, a layer of wax is applied with a thickness exceeding the thickness of the final metallic shell. The final shape of the sculpture is then cut on the exterior surface of the wax, so that the wax layer has a thickness corresponding to the thickness of the outer metallic shell. The cut wax layer is then covered with plaster, and heat is applied to melt the wax and allow the wax to drip out through an opening in the outer plaster layer.

Abstract: A pair of tape measures are mounted in side-by-side relationship on a common axial shaft with a clutch plate between them operable by a crank on the shaft. Pressure may be applied to the reels and in turn to the clutch plate by thumb adjustment nuts on the outer ends of the shaft, such that the reels may turn together or remain stationary as the shaft is turned. The method of using the measuring device to lay out a lot involves attaching the free end of one tape to a stake at one corner and then walking to a second corner while the first tape is being unreeled. The free end of the second tape is attached to a stake at the second corner, and then the measuring device is moved to a third corner with the tapes being appropriately extended or contracted, and the stake is placed at the intersection of the measured distances on both tapes. Next, the measuring device is moved to the fourth corner, and a stake is placed at the intersection of the known measured distances on each of the tapes.

Abstract: A Journalist Teaching Aid for Journalists is provided which comprises in combination: a plurality of master layout boards constructed of a material such as glossy paper, mylar or the like to permit readily detachably mounting adhesively backed materials thereon, the master layout boards are used to simulate pages of publications such as newspaper, magazines, tabloids, books, and the like; adhesively backed strips of materials such as glossy paper card stock, plastics such as mylar and the like having a plurality of said strips covering a plurality of dimensions for simulating flags, nameplates, logos, headlines, mastheads, artwork and the like used in publishing said pages of publications; adhesively backed strip holders for detachably mounting said strips thereon when not in use; and a plurality of miniature card stock layout boards for use by the journalist in drafting thereon a preliminary page layout.

Abstract: An apparatus is disclosed for holding a plurality of modular components against a surface. A fixture prepositions the components and a vacuum develops a uniform pressure which presses and holds the fixture and objects against a surface. The surface may be curved, vertical, or overhead and since local load concentrations are avoided, fragile ceramic tiles may be installed using the apparatus.

Abstract: A real estate electro tape is provided that measures the length of an interior or exterior wall or other similar structure using optical means. A sonic tape is used to measure the perpendicular distance from the device to the interior or exterior wall. Two steerable lasers are then used to determine the angles between the perpendicular and the beams aimed at the wall edges. An algorithm is applied to the angular and perpendicular distance data to obtain the length of the wall. A microprocessor performs the calculations, the results of which are displayed on an electro optical display.