The practical draughtsman's book of industrial design and machinist's and engineer's companion : forming a complete course of mechanical, engineering and architectural drawing . r indrawing a curve. A small drawing-pen, c, ingeniously formedout of a slip of steel bent over the wire, a, and screwed to a brassbush, so as to form two broad nibs, is arranged to slide from endto end of the wire, being adjustable at any point by stiff friction,caused by a spring, which, fitting a groove in the wire, retains thevertical position of the pen. In drawing a curve, the rod or wireennying the pen is set at
The practical draughtsman's book of industrial design and machinist's and engineer's companion : forming a complete course of mechanical, engineering and architectural drawing . r indrawing a curve. A small drawing-pen, c, ingeniously formedout of a slip of steel bent over the wire, a, and screwed to a brassbush, so as to form two broad nibs, is arranged to slide from endto end of the wire, being adjustable at any point by stiff friction,caused by a spring, which, fitting a groove in the wire, retains thevertical position of the pen. In drawing a curve, the rod or wireennying the pen is set at right angles with the slider, b, which isdrawn in a right line along the edge of a ruler, whilst the wire carrying the pen is left tofind its way from its initialangular position, to that ofa line in the same plane asthe slider; and, in doingthis, the pen describes thecurve we have 3 is a vertical sectionof a millstone arrangementon this system, showinghow the gradual variationof the curvature, in rela-tion to the increasing dis-tance of the parts from thecentre of motion, equalizesthe rubbing pressure in the most perfect manner. The same sketch ?DB a. also shows the adaptation of the principle to footsteps, togetherwith a new system of lubrication of these surfaces so liable toextreme abrasion. Tho oil supply is kept in an elevated vessel, a,whence a pipe, b, proceeds downwards to the footsteps, uponwhich a pressure is thus constantly kept by the oil column, a stop-cock being introduced to regulate tho supply. Mr. Schiele now makes independent or self-contained flour-millsof this kind, of such simplicity and compactness, that four com-plete mills, or sets of stones, placed together, may be worked in aroom 10 feet square ; a single shaft driving the set, from the cen-tre, by means of a horizontal band-pulley, from which endlessbands pass to corresponding pulleys on the spindle above theupper stone. In mills of this kind, when by wear the runner hassunk three i
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Keywords: ., bookcentury1800, booksubjectarchitecturaldrawing, booksubjectmec
