Rudimentary treatise on the erection of dwelling-houses : illustrated by a perspective view, plans, elevations, and sections of a pair of semi-detached villas with the specification, quantities, and estimates and every requisite detail, in sequence, for their construction and finishing / by . and c, the adjust-ing screw, to set these points to the re-quired radius. Tabular Compasses. The engraving on page 75 representsthis instrument. It may be used as an ordinary pair ofcompasses, either with two fine points, a pen point, or apencil point, and is capable of describing circles to any
Rudimentary treatise on the erection of dwelling-houses : illustrated by a perspective view, plans, elevations, and sections of a pair of semi-detached villas with the specification, quantities, and estimates and every requisite detail, in sequence, for their construction and finishing / by . and c, the adjust-ing screw, to set these points to the re-quired radius. Tabular Compasses. The engraving on page 75 representsthis instrument. It may be used as an ordinary pair ofcompasses, either with two fine points, a pen point, or apencil point, and is capable of describing circles to anyextent of radius from an eighth of an inch to fourteeninches and a-half, and with the advantage of reversingpoints which may be changed from pen to pencil, &c,without deranging the setting of the instrument whenopened to any definite extent. a and b are the two principal legs of the instrument,consisting of tubes movable about a very nicely con-structed joint at c. Within these are two sliding tubese and d, which draw out their whole length, and areaccurately fitted to the principal tubes a and b, so that. TUBU LAR COMPASSES. 75 they may be drawn out to their required extent with asmooth and steady motion, not subject to sudden stop-pages, or to move with equally sudden jerks, a proof ofbad workmanship, but uniformly, and not too easy.*To assist in this, their inner extremities are made toact as springs within tubes,wherein they slide, thus increas-ing their friction. The outward extremity ofeach of the sliding tubes eand d terminates in a squareheaded joint, a and b; uponthese move the pieces c and d,which carry the point limbs ofthe compasses. The joints aand b in this instrument cor-respond with the joints c andd of the compasses with mova-ble points as before described,and are used for a similar pur-pose, namely, to set the pointlimbs perpendicular to thepaper, and consequently paral-lel to eacl other, at whateveropening the legs of the com-passes may be extendetl to. In ou
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectarchitecturedomestic
