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Contents I I I LIFTIXG D E V I C E S Lerer and slip knot The simple pulley Simple pulley with ratchet and pan-l imtipk Puck; s The Chinese windlass The Arabian grappling device Shadouf The Chinese spoon-tilt hammer The Cornish man engine I V M E C H A N I S M S Coin-in-the-slot machine The Greek puppet theatte mechanism ‘The Chinese south-pointing chariot Foliot and verge escapement The wrapping escapement 30 30 32 3 4 36 38 40 42 4 4 46 48 48 50 52 54 56 v V I VII M A C H I N E S F O R PUMPIXG AZD \V.lTER R A I S I N G j8 Archimedean snail Tympanum Ctesibian pump The rag and chain pump The suction pump The cow pump The diaphragm pump The hydraulic ram 3 60 ! 62 6.1 65 68 69 70 B L O W I N G M A C H I N E S F12 The valveless bellows 7= The Chirlse double-acting bloeer i-1 HZ&T E N G I N E S 76 Temple doors. j6 Hero’s whirling Aeolipile 78 Chapter I Materials and Tools for making \\‘orlting Models of Machines 8 I ---7 .I, Fig. I/I Drtails of prqmrtional dividers 9': Pmportivnul lDir+der-s. ‘?officicnt detni! has been give” for each of the tcodels in rhr pcrspectivr drawings (which arc to scale) to enable anyone to “lake them by scaling otl’ dimensior‘s iv; anv of the three plants, namely, up and dwvn, sideways. and hunt and b a c k . ‘l’he q u i c k e s t WIV of doirlg this is !?!- “wans of a “nir of - proportiwx~l d i v i d e r s , I - i g . I ,:I. ‘l‘he construction of the dividers car> .T ‘-. ::a” from the d r a w i n g whue the “eccssity for machinin; i: ~i:~iizl -,i;rfaces has been avoided by using square-section si des of mw!, prcfe-ably steel with R hr.~s b!ock sliding between. ‘l‘hc points at either end of the “.i:,idcrn should p~i~r,,l-i~ I, e nude of steel a n d ca” bc s h a p e d by tiling from square n1atcrial. ‘Yu me the dli-idcrs the scale in inches lnarked on every model drawing must bc used and the distance hetwen the two points at one end of th:: dividers sl:t to say h in on the vertical scale, then the fulcruln of the di>,iders i:; atiju::tc d until the distance between the two points at the other end of the dividers is 0 in. The fulcrum ca” then be adjusted for tighttress and the real lengths in the vertical direction of any part of the model ca” he dctcrxnined by placing the two pol:lts on the right-ha”d side of Fig. lir against the vertical distance o” the drawing of any line it is desired to measure, when the distance between the point; at the left-hand side wil! be the actual vertical distance in question on the “lodei. .A similar pro- cedure can be followed with regard to the other two lines on the scale in inches, marked on each of the drawings. It should he noted that once the fulcrum has been tightened fvr the vertical position, the same setting appl;es to each of the other planes shower on the scale in inches, though measurement made at intamediate angles will not be correct if they are scaled in the same way. Drazcings. Rlost of the drawings in this book are isometric though a few are oblique. Isometric sketches such as Fig. Z:I are ~cnerally considered to give a representation that is more e~zl!v appreciated by the beginner than the normal engineering dF-ti<;n;;i &wing plan, elevation and side view which are known as orthogonal pro- jections. In a few cases, e.g. Figs. z/S, 315, 4/r, 5/3, orthogonal projections have been given because all the necessary details of thae mode!s could not be conveniently represented in isometric drawings. Intpnxised Eyuipmenf. A great many other tools that are avai!ahle might have been suggested but in the writer’s view, they are not essential. For instance, sets of taps and dies are nice things to have but their purchase can hardly be justified for this sort of work when bolts, nuts and screws can be obtained so easily and cheaply without having to make them for oneself. ‘l’here are other tools which though not essential would be a great convenience and would speed up the making of many of the mode!s. Chief among these is the portable electric drill with its various attachments for sawing, grinding, and so on. It will be noticrd that in many cases household utensils and articles oi commerce that can be purchased from the ironmongers have been used instead of making parts specially for the models. Thus plastic bilckcts and transparent plastic boxes have been freely usedPsometimcs modified by drilling or cementing the lids on to make them airtight. Likewise, broom-shanks and coffee- table legs with scrcwed ends have been found to have uses other than those originally intended. The reader will find that to use his ingenuity in this way-by adapting finished or partly finished parts to his particula; uses, is in itself a rewarding challenge which often saves a great deal of time--and sometimes money as ~vvell. Fig. I/Z Use of proportional dividers Chapter II Some Ancient Machine Tools Bow Drill 1)rilling is d o n e by holding the drill shaft vcr:ically with t h e palm piece in the left hand and dra\\~ing the 1~01~ backwards and forwards XI hercnpon the drilling shaft and drill arc rotated alter- nately clock\\isc a n d anti-clock\Csc, while the bow maintains sul%icnt wnsion in the cord to provide enough friction between the cord and the drill shaft to prewnt slipping; thus the drill shaft is rotated. Suficicnt do\vnw;trd pressure must be maintained on the drill by the palm piece to force the drill down into the \vork. The palm piece sholdd have a hole or socket into \rhich the upper end of the drill shaft enters. The drilling bit needs to be sharpened from time to time whether it is stone or metal so that a cutting edge is maintained. ‘1%~ drill bit is Hattencd into a batswing shape, (‘l‘wist drills of the type used today in rotary drilling machines wre invented about a hundred years ago,) In the bow drill, the backwards 2nd forwards reciprocating motion of the hand ii converted into clockwise and anti-clockwise rotary motion of the drill head. SCALE IN INCHES Fig. Z/I Bow drill Egyptian cabinet-makers. iXIastaba of Tiye, Saqqara, zj4.x B.C.