,this file was produced from page images at the ,internet ,archive4 ,transcriber's ,note ,this book was transcribed from scans of the original found at the ,internet ,archive4 ,i have rotated some images4 ,tables are treated as images4 ,the back of the book contains ads for other books1 which ,i have treated as additional chapters4 ,,how ,,to ,,build ,a #bj-;,,foot 99,,bi-,,plane ,,glider99 ,a ,practical ,handbook on the ,construction of a ,bi-plane ,gliding ,machine1 ,enabling an ,intelligent ,reader to ,make ,his ,first ,step in the ,field of ,aviation2 ,with a ,comprehensive ,understanding of the ,principles ,involved4 ,,by ,,alfred ,,powell ,,morgan ,editor ,mechanical and ,electrical ,department of the 8,boy's ,magazine40 ,,new ,,edition1 ,,revised ,,new ,,york ,,spon ,,chamberlain1 #abc ,,liberty ,,st4 ,,london 99,e4 ,f4 ,n4 ,,spon1 ,,limited1 #eg ,,haymarket1 ,s4,w499 #aiab ,copyright1 #aiji1 by ,spon ,chamberlain4 ,,how ,,to ,,build ,a #bj-;,,foot ,,bi-,,plane ,,glider ,,preface ,gliding flight is a comparatively new field for the amateur to delve in1 but the time has arrived when it is being extensively taken up both as a sport and a means of experiment4 ,many very costly aeroplanes have failed to fly because of man's total inexperience in the art of flying4 ,all of the great aviators now before the world1 whose machines are the result of their own genius learned to fly before succeeding in a motor driven machine4 ,the ,wright brothers spent no less than three years on the sand dunes near the coast of ,north ,carolina making gliding flights4 ,they approached the difficulties in a methodical manner1 working out each problem and determining which was the best means of accomplishing a certain result4 ,to control the tendency to pitching1 they devised an elevation rudder and attached it to the front of their machine4 ,the next step was to determine whether equilibrium should be maintained by shifting the centre of gravity or if there was not a better method and they introduced what is probably the most valuable feature of the modern aeroplane1 namely the warping or twisting of the ends of the planes to secure lateral stability when a gust of wind strikes one end of the machine4 ,in this manner the ,wright's continued their experiments until every move had become a matter of habit and to balance and guide an aeroplane was almost an instinct4 ,a gasoline engine was then fastened in the machine and connected to drive two screw propellers at the rear4 ,dec4 #ag1 #aijc the machine flew for a few seconds4 ,the leaps and bounds with which aviation has since progressed both in the hands of the ,wrights and others is a matter too well known to be repeated4 ,there is therefore no excuse necessary to be made for this little book1 coming as it does at this time and it is sincerely hoped that it may interest and lead many to experiment first and build their aeroplane afterward so that when their machine is complete it may be practical and not intended to operate in some lift-yourself-by-your-boot-straps manner4 ,,how ,,to ,,build ,a #bj-;,,foot ,,bi-,,plane ,,glider 4444444444444444444444444444 ,,preface 4444444444444444444444444444444444444444 44444444444444444 ,,chapter ,i4 ,the ,framework4 444444444444444444444444444444444444444 ,,chapter ,,ii4 ,covering the ,planes4 44444444444444444444444444444444 ,,chapter ,,iii4 ,trussing4 4444444444444444444444444444444444444444 44 ,,chapter ,,iv4 ,gliding4 4444444444444444444444444444444444444444 4444 ,,chapter ,v4 ,remarks4 4444444444444444444444444444444444444444 44444 ,,books ,,for ,,aviators 4444444444444444444444444444444444444444 444444 ,,books ,,on ,,aeronautics4 4444444444444444444444444444444444444444 444 ,,model ,,aeroplanes4 4444444444444444444444444444444444444444 4444444 ,,good ,,books ,,for ,,wireless ,,operators4 444444444444444444444444444444 ,fig4 #a ,horizontal ,beam 4444444444444444444444444444444444444444 4444 ,fig4 #b4--,strut4 4444444444444444444444444444444444444444 444444444444 ,fig4 #c4--,position of ,struts4 444444444444444444444444444444444444444 ,fig4 #d4--,strut clamp4 4444444444444444444444444444444444444444 444444 ,fig4 #e4--,stanchion4 4444444444444444444444444444444444444444 44444444 ,fig4 #f4--,stanchion socket4 4444444444444444444444444444444444444444 4 ,fig4 #g4--;,eyebolt4 4444444444444444444444444444444444444444 4444444444 ,fig4 #h4--;,assembly of stanchion1 socket beam1 strut and clamp4 444444 ,fig4 #i4--,rib4 4444444444444444444444444444444444444444 44444444444444 ,fig4 #aj4--,rib clamp4 4444444444444444444444444444444444444444 4444444 ,fig4 #aa4--,plan ,view of ,planes showing ,ribs4 444444444444444444444444 ,fig4 #ab4--;,arm piece4 4444444444444444444444444444444444444444 4444444 ,fig4 #ac4--,parts of rudder framework4 4444444444444444444444444444444 ,fig4 #ad4--;,corners of horizontal rudder plane4 4444444444444444444444 ,fig4 #ae4--;,complete framework of rudder4 4444444444444444444444444444 ,fig4 #af4--;,cross bar4 4444444444444444444444444444444444444444 4444444 ,fig4 #ag4--,rudder ,sockets1 or ,clamps4 4444444444444444444444444444444 ,fig4 #ah4--;,arrangement of ,armpieces and ,rudder ,cross ,bar4 44444444444 ,fig4 #ai4--;,complete ,framework ,ribs on ,lower ,plane ,not ,shown 444444444 ,fig4 #bj4--,method of hemming up edge of cloth4 4444444444444444444444 ,fig4 #ba4--,section of cloth hemmed1 and reinforcing strips sewn on4 4 ,fig4 #bb4--,trussing ,of ,cells4 444444444444444444444444444444444444444 ,fig4 #bc4--,plan and ,elevation ,views of ,piano ,wire ,bracing4 4444444444 ,fig4 #bd4--,method of anchoring wires 44444444444444444444444444444444 ,fig4 #be4--;,bicycle spoke turnbuckle4 44444444444444444444444444444444 ,fig4 #bf4--,top view1 showing how streams of air divide4 4444444444444 ,fig4 #bg4--,showing how air currents pass over objects4 44444444444444 ,fig4 #bh--;,action of aeroplane4 44444444444444444444444444444444444444 ,fig4 #bi--,ready to ,start 4444444444444444444444444444444444444444 4444 ,fig4 #cj--,lines of ,flight 4444444444444444444444444444444444444444 444 ,,chapter ,i4 ,the ,framework4 99,a gliding machine991 more often popularly termed a glider1 is simply a motorless aeroplane1 operating by force of gravity to carry its passenger sailing through the air from the top to the foot of a slope4 99,the glider99 described herein is the type developed by ,octave ,chanute and may be considered as the parent of the biplane machines with which the world has lately become so familiar4 ,the machine is known as a biplane since its supporting surface is in the form of two superimposed trussed planes vertically above each other and having a tail in the rear for the control of direction4 ,there is always a tendency among experimenters to depart from the design and dimensions of any machine or apparatus offered for construction4 ,this1 since it develops originality is a good indication1 but most of those who will undertake to build a glider are attempting something altogether new and so any radical change from the instructions in this little booklet are unadvisable4 ,it is better at first to benefit by the experience of others4 ,the glider here described is considered as the standard of the biplane type4 ,it has an active supporting surface of #aeb square feet which is sufficient to carry the weight of an ordinary man4 ,a machine having a larger surface will support the same weight when moving through the air at a slower speed1 but larger surface means an increase in some of the general dimensions4 ,an increase in surface by lengthening the planes will make the machine much harder to keep on an even keel1 while increasing their depth in the direction of flight will require greater agility on the part of the operator to keep the centre of gravity in the proper position4 ,a larger machine also means more weight and a heavy machine is hard to make a landing with4 ,on the other hand a light glider is dangerous and will not stand any rough usage4 99,the cost of the glider991 provided the construction is accomplished by the intending owner is so low as to place it within the reach of any person of ordinary means4 ,the expenditure for raw materials varies greatly4 ,it is usually a little less than #bj4jj and should not exceed #ce4jj4 ,a finished glider is worth from #ej4jj to #ajj4jj depending whether or not more than one is made at a time4 99,housing499 ,one of the first considerations is usually the housing and storing of the glider1 but the machine under consideration is so designed that it may be quickly taken apart or knocked down and be put away in the cellar1 under the porch or in some other out of the way place4 99,the framework99 is composed entirely of selected spruce1 straight grained and free from knots4 ,spruce is very dense and tough but yet one of the lightest of woods4 99,the dimensions99 given are for the finished pieces after they have been planed up4 ,the usual method of finishing wood for aeronautical work1 so that it has a hard glassy surface and offers little resistance to the air is first to give it a thorough brushing over with hot glue and water4 ,it is rubbed down after drying1 using fine sand paper4 ,the wood is then given a coat of thin shellac4 ,this is rather a tedious operation and instead some may prefer to first smooth up the wood by sand papering and giving it a coat of spar varnish4 ,the corners of all the woodwork are rounded off so as to reduce the resistance offered to the air4 99,horizontal beams994 ,the principal members of the planes when smoothed up should measure #bj feet long1 #a #a_/b inches wide and #c_/d inches thick4 ,four of these beams are required4 ,in some lumber yards1 twenty foot spruce free from knots is very hard to secure and so instead1 two #aj foot pieces may be spliced together at the centre as shown in ,fig4 #a4 ,the splicing strip is #e feet long and has the same cross section as the beams1 save for a distance of one foot from each end where it begins to taper down to #a_/d inch thick4 ,six holes are bored through the splicing strip and the beams so that they may be fastened together by means of six #c_/af inch round headed stove bolts4 ,the holes are located so that the space between the two centre bolts is six inches while the others are located one foot apart4 ,a large washer having a small hole in the centre is placed under the head of each bolt as well as the nut4 ,illustration3 ,fig4 #a ,horizontal ,beam 99,struts499 ,each pair of horizontal beams are held parallel to each other and three feet apart by six horizontal struts4 ,the form of these struts is illustrated in ,fig4 #b4 ,they are three feet long and #a_/b x #a #a_/d inches in cross section4 ,a notch #a #a_/b x #c_/d inches is cut in each end so as1 to form a projection #a #a_/b x #a_/b x #a_/b inches4 ,the location of the struts in the plane is illustrated in ,fig4 #c4 ,the two in the centre are two feet apart and the others respectively #d feet #f inches and #i feet on either side4 ,the struts on the upper plane are placed so that the projections come above the horizontal members4 ,those on the lower plane are placed just the opposite1 that is so that they come on the under side4 ,illustration3 ,fig4 #b4--,strut4 ,they are fastened with one or two small wire nails and then secured by means of a clamp4 ,two dozen clamps are required4 ,they are bent out of a strip of sheet brass one sixteenth of an inch thick1 #c #g_/h inches long and #a inch wide4 ,the ends are rounded and a #a_/d inch hole located and bored in each as in ,fig4 #d4 ,illustration3 ,fig4 #c4--,position of ,struts4 ,the clamp also serves to protect the under side of the beam from the action of the nuts on the ends of the eyebolts4 ,the method of fastening the clamp is detailed a little later4 ,illustration3 ,fig4 #d4--,strut clamp4 99,stanchions994 ,the planes are separated by twelve stanchions1 four feet long and #g_/h of an inch in diameter4 ,illustration3 ,fig4 #e4--,stanchion4 ,they are rounded and smoothed up so that the ends will fit snugly into the socket illustrated in ,fig4 #f4 ,these sockets may be purchased already bored and finished or can be procured at a foundry4 ,they are preferably made of aluminum which metal is at once light and strong but brass or even iron may be used if it is necessary to avoid expense4 ,illustration3 ,fig4 #f4--,stanchion socket4 ,there are other methods of joining the stanchions to the beams but the use of the socket is recommended because it is the strongest method and also permits the glider to be readily taken apart4 ,the base of the socket is #c #a_/d inches long1 #a #a_/d inches wide and #a_/d of an inch thick4 ,the cup has an internal diameter of seven eighths of an inch and an outside diameter of one inch and one quarter4 ,it is one inch high above the base4 ,two #a_/d inch holes are bored #a #g_/h inches apart in the base4 ,two smaller holes #a_/h inch in diameter are bored #g_/af inch nearer the ends of the base than the larger holes4 99,the wooden pattern99 is made from the dimensions indicated in ,fig4 #f4 ,it is thoroughly smoothed up by rubbing with sand paper and then given a coat of shellac4 ,all parts should have a very slight taper towards the top so that the pattern may be withdrawn easily from the sand mould4 ,illustration3 ,fig4 #g4--;,eyebolt4 ,if the interior of the mould is coated with lamp-black1 the castings will require no other finishing than boring the holes4 ,two dozen of these sockets are required4 ,six are fastened to each of the four horizontal members by means of round headed wood screws which pass through the smaller holes in the base4 ,the sockets are located exactly opposite the ends of each strut so that when the stanchions are in place1 they will be separated by the same distances but all lie in a plane at right angles to that in which the struts are4 ,a #a_/d inch hole is bored through the horizontal beam directly under each one of the #a_/d inch holes in the base of the socket4 ,these holes permit an eyebolt to pass through4 ,the eye bolt is illustrated in ,fig4 #g4 ,the stock is #a_/d inch in diameter and should be at least two inches long under the eye4 ,illustration3 ,fig4 #h4--;,assembly of stanchion1 socket beam1 strut and clamp4 ,the diameter of the eye is one half an inch4 ,these eye bolts are obtainable already threaded and ready for use with a nut and washers1 but can be procured somewhat cheaper in blank form and threaded by the purchaser4 ,four dozen are necessary1 two for each socket4 ,the eye bolts pass through the socket and beam1 coming out on the under side directly opposite the holes in the strut clamp4 ,a nut placed on the under side as in ,fig4 #h will then hold the clamp tightly against the under side of the beam and secure the position of the strut4 99,ribs499 ,forty one ribs support the cloth forming the surfaces4 ,they are each one half an inch square in cross section and four feet long4 ,illustration3 ,fig4 #i4--,rib4 ,they are fastened to the horizontal members one foot apart1 flush with the front and projecting one foot in the rear4 ,one or two small wire nails are used to fasten the front ends and then a clamp placed over them and screwed down with two ,no4 #e round headed wood screws1 one half an inch long4 ,a small brad awl should be used to make a hole before starting the screw and so avoid any possibility of starting a split in the wood4 ,the clamps are bent out of sheet copper strips1 #b #a_/d inches long and #e_/h of an inch wide4 ,the ends are rounded and a hole bored through which the screws may pass4 ,the surfaces of the planes are curved to give them an increased carrying capacity and add to the gliding power4 ,illustration3 ,fig4 #aj4--,rib clamp4 ,the best method is to steam the ribs and then bend them so that when they dry they will retain their curve and not tend to push the horizontal beams apart4 ,only a very slight curve should be given and the amount of curvature should be the same for all the ribs4 ,some designers construct gliders having flat planes1 intending that the pressure of the air underneath the fabric shall produce a natural curve but such a method is exceedingly poor practice and results in a very inefficient machine4 ,the ribs must be perfectly rigid and the frame of the whole machine strongly trussed so that it cannot possibly be distorted by the air pressure4 ,the following extract from the report of the ,smithsonian ,institute well illustrates this point4 ,this new launching piece did its work effectively and subsequent disaster was1 at any rate1 not due to it4 ,but now a new series of failures took place1 which could not be attributed to any defect of the launching apparatus1 but to a cause which was at first obscure2 for sometimes the aerodrome1 when successfully launched would dash down forward and into the water1 and sometimes 7under apparently identical conditions7 would sweep almost vertically upward into the air1 and fall back although the circumstances of flight seemed to be the same4 ,the cause of this class of failures was finally found in the fact that as soon as the whole machine was up-borne by the air1 the wings yielded under the pressure which supported them1 and were momentarily distorted from the form designed and which they appeared to possess4 ,momentarily1 but enough to cause the wind to catch the top1 directing the flight downward1 or under them1 directing the flight upward1 and to wreck the experiment4 ,when the cause of the difficulty was found the cure was not easy1 for it was necessary to make this great sustaining surfaces rigid1 so that they could not bend40 ,the report in question refers to the experiments conducted with ,professor ,langely's model aerodrome4 ,some experimenters claim that the parabolic curve gives the greatest lift with the least power required for propulsion but it can be safely doubted4 ,the ,wright machine is probably the most efficient in existence4 ,their curve is very nearly the arc of a circle and is not of the parabolic form4 ,four per cent is about the proper curve to give the planes of a glider4 ,this is about two inches for ribs four feet long4 ,after fastening the front end of the ribs1 curve them up in the centre by pressing down on the loose and at the rear4 ,then nail the rib to the rear beam with a small wire brad and screw on the clamp4 ,the nails prevent the ribs from slipping longitudinally while the clamps serve to prevent them from moving sideways or pulling off when the fabric is under the pressure of the air4 ,fig4 #aa is a plan view of the top and bottom planes4 ,twenty one ribs1 each one foot apart are used on the upper plane4 ,only twenty ribs are required on the bottom surface because an opening two feet wide must be left in the centre for the body of the operator4 99,arm pieces499 ,the operator is supported in the machine by two strips of wood passing under his armpits4 ,these armpieces are #c feet long1 #a inch wide and #a #c_/d inches deep4 ,illustration3 ,fig4 #aa4--,plan ,view of ,planes showing ,ribs4 ,they are fastened to the horizontal beams by means of a #c_/af inch round headed stove bolt4 ,the distance between should be just wide enough to be comfortable and is variable with the breadth of the operator between his shoulders4 ,thirteen inches is about the proper distance for the average person4 ,the upper side of the arm pieces is rounded so that they will not be quite so uncomfortable as they would be if left square4 ,it is not a good plan to pad these pieces by wrapping them with cloth for it will impede the movements of the body in balancing4 ,illustration3 ,fig4 #ab4--;,arm piece4 99,rudder499 ,the rudder is composed of two planes at right angles to each other and in the rear of the main surfaces4 ,the vertical portion keeps the machine headed into the wind and causes it to glide in the direction in which it is started or head on into the wind4 ,the horizontal rudder steadies the machine longitudinally and prevents the machine from suddenly diving or pitching4 ,neither of the rudder planes are movable4 ,the separate parts composing the framework are illustrated in ,fig4 #ac4 ,illustration3 ,fig4 #ac4--,parts of rudder framework4 ,the cross section of all the sticks is the same1 namely one inch square4 ,the two long beams1 ,a1 are #h feet #aa inches long4 ,the two uprights1 ,b1 each #c feet #aj inches long from the vertical members of the directional plane4 ,the horizontal plane is made up of six horizontal strips1 two of them1 ,c1 six feet long and four1 ,d1 two feet in length4 99,the horizontal plane99 is fitted together with half and half lap joints4 ,it is first fastened with nails and then reinforced with brass corner braces4 ,illustration3 ,fig4 #ad4--;,corners of horizontal rudder plane4 ,corner braces are also used to strengthen the vertical plane4 ,illustration3 ,fig4 #ae4--;,complete framework of rudder4 99,the rudder beams99 are stepped into sockets on the body of the machine so that the rudder is detachable4 99,a short cross bar99 #b feet inches long and #a #a_/d x #c_/d inches in cross section1 is fastened between the two centre struts of both planes at a point eight inches forward of the rear beams4 ,these cross bars carry one of the sockets mentioned above as also do the rear horizontal beams4 ,the cross bar and sockets in the upper plane should be directly over those in the lower plane but in an inverted position4 ,illustration3 ,fig4 #af4--;,cross bar4 99,the construction of the sockets99 is illustrated in ,fig4 #ag4 ,the smaller one is fastened to the cross bar and is bent out of a strip of #a_/af inch sheet brass #d #a_/b inches long and #c_/d of an inch wide4 ,the larger socket is the same length and thickness but is #a #a_/d inches wide and is fastened to the horizontal beam4 ,two of each size are required4 ,the ends are rounded and a #c_/af inch hole bored in each so that a #c_/af inch round headed stove bolt may be used to fasten the sockets to the framework4 ,illustration3 ,fig4 #ag4--,rudder ,sockets1 or ,clamps4 ,illustration3 ,fig4 #ah4--;,arrangement of ,armpieces and ,rudder ,cross ,bar4 ,illustration3 ,fig4 #ai4--;,complete ,framework ,ribs on ,lower ,plane ,not ,shown ,a hole is bored in the centre of the top of the smaller sockets so that a bolt may be passed through the rudder beam and cross bar to prevent the former from pulling out4 ,the two sockets in each plane must be in perfect alignment and lie on a line drawn at right angles to the horizontal members through the centre of the planes4 ,in ,fig4 #ae it will be noticed that four bolts pass through each plane near the corners4 ,the bolts are #c_/af inches in diameter and serve to fasten the piano wires which brace the vertical and horizontal plane to each other4 ,the complete framework of the glider without the tie wires and the ribs on the lower plane will appear as in ,fig4 #ai4 ,from ,spon ,chamberlain ,,chapter ,,ii4 ,covering the ,planes4 ,the surfaces of a motor driven aeroplane are usually made of some material which is practically air tight4 ,the ,herring-,curtiss ,co41 use ,baldwin's rubberized silk1 while most of the foreign aviators prefer a balloon cloth known under the name of continental4 ,ordinarily the surfaces of a glider are not covered with any preparation to make them air tight and is not necessary1 but since it will considerably increase their efficiency it is offered as a suggestion to those who are able or care to undergo the expense4 99,aero varnishes99 for this purpose are obtainable in the market and may be applied with an ordinary brush or by immersing the fabric4 ,one gallon will cover approximately #ajj square feet of ordinary ,cambric1 although much depends upon the weave4 ,the more open or coarser the goods1 the more varnish it will require1 while fine fabrics take the least amount4 ,varnish is expensive and is not considered in the estimate of cost made at the beginning of the book4 99,the surfaces99 are formed of cambric or muslin stretched tightly over the ribs4 ,thirty yards of material1 one yard wide will be sufficient to cover the machine1 including the rudders4 ,seven strips #d feet #f #a_/b inches long are cut and sewed together along the selvages so that a surface #d feet #f #a_/b inches wide and a little over #bj feet long is formed4 ,twenty one strips1 #d feet #f #a_/b inches long and #a #a_/b inches wide are cut and sewed to the surface at right angles to the long edges and one foot apart1 between their centre lines4 ,the edges of these strips are turned under #a_/d of an inch on each side so that they form a reinforcement #a inch wide which will come directly above each rib4 ,illustration3 ,fig4 #bj4--,method of hemming up edge of cloth4 99,reinforcing499 ,the long edges of the surface are then doubled back and hemmed1 turning under #a_/d of an inch and forming a #c inch hem as illustrated in the upper part of ,fig4 #bj4 ,this #c inch hem is then doubled back one inch and sewed again so that the result is a two inch hem1 composed of two thicknesses of cloth save for one inch back from the edge where it is made up of four thicknesses4 ,this reinforcing is necessary to avoid ripping and tearing the cloth out from under the tack heads when it is under pressure during a flight4 ,illustration3 ,fig4 #ba4--,section of cloth hemmed1 and reinforcing strips sewn on4 99,the bottom planes499 ,the cloth on the bottom planes is made up of two sections1 divided by the space in the centre of the lower plane which the operator occupies4 ,these sections are made and reinforced in exactly the same manner as that for the top plane just described but are one foot less than half as long4 99,the cloth is tacked99 over the front horizontal beam and then stretched tightly over the curved ribs and fastened with tacks at the ends4 ,fasten the corners of the cloth first and smooth it out before driving the tacks in the ribs4 ,ordinary brass headed upholsterer's nails are used but they should not be long enough to pass all the way through the ribs4 ,a strip of felt #c_/h of an inch wide and four feet long is laid on the cloth directly over each rib so that it comes between the head of the tack and the cloth4 ,this precaution may seem unnecessary to some1 but it greatly reduces the liability of having the cloth tear when under pressure4 ,the tacks along the ribs are spaced about #d inches apart ,a heavy weight held against the under side of the rib by an assistant1 when the tacks are driven in will provide a firm foundation to hammer against4 ,a very good method of fastening the cloth to the ribs is to sew a pocket on the under side of the surface and into which the ribs may be slipped4 ,the rear ends of the ribs may be fitted with metal tips by tapering the end down until it is round and measures #a_/b inch in diameter4 ,a #a_/b inch brass ferrule such as that used on file handles is then forced on4 99,the rudder planes99 are covered on both sides4 ,the fabric is stretched tightly over the frame and then tacked along the edges4 ,the edges should be turned under before tacking so that there is no possibility of the cloth tearing out4 ,the cloth at the ends of the planes should be securely fastened to the struts by means of tacks4 ,this will relieve the ribs of some of the strain and correct a tendency for them to pull in towards the centre4 ,,chapter ,,iii4 ,trussing4 ,the strength of the glider lies in its proper trussing with piano wires which when tightened up should so brace the framework that it will support without appreciable sag or strain1 a heavy man hanging from the arm pieces and the ends of the planes resting on a pair of carpenters' horses4 ,two methods of trussing the planes are illustrated in ,fig4 #bb4 ,the machine is divided into five cells the vertical boundaries of which are formed by the stanchions4 4 99,the first method99 illustrated is the one used in this case for the glider4 ,it is somewhat simpler than the second and does not require the use of any turnbuckles4 ,each wire is fastened to one of the eyebolts on the horizontal beams and then run diagonally across to the socket on the opposite beam in the other plane1 considering front and rear to be opposed4 ,four of these diagonal wires1 represented by ,j in ,fig4 #bc brace each of the four large cells4 ,the middle cell cannot be trussed up in this manner because the wires would interfere with the body of the operator4 ,so the rectangles formed by the two centre struts with the upper horizontal beams and the two centre rear stanchions with the rear horizontal beams of the upper and lower planes1 are braced by means of wires running across their diagonals4 ,illustration3 ,fig4 #bb4--,trussing ,of ,cells4 99,the rudder99 is stiffened and trussed to the planes by sixteen wires4 ,two of these ,f and ,h run from the top of the vertical rudder plane to the lower sockets in the rear1 #d #a_/b feet from the ends of the planes4 ,the corresponding pair ,e and ,g run from the bottom of the rudder to the top sockets of the same stanchions4 ,four wires ,a1 ,b1 ,c1 ,d steady the horizontal plane and run from its corners to the sockets in which the rudder beams are stepped on the frame of the glider itself4 ,the remaining eight1 indicated by ,i in the illustration brace the horizontal and vertical planes of the rudder to each other4 ,fig4 #bd illustrates the method of anchoring piano wires4 ,the wire is first passed through a short piece of #a_/h inch copper tubing about #c_/h of an inch long1 then through the eyebolt4 ,the end is doubled back passed through the tube again but now in a reverse direction4 ,by bending the extreme end of the wire over in the form of a hook and shoving the tube down close to the eye bolt1 the wire is secured and cannot pull out4 ,the other end of the wire is fastened in the same manner but before the end is bent over into a hook1 the wire must be first pulled tight4 ,illustration3 ,fig4 #bc4--,plan and ,elevation ,views of ,piano ,wire ,bracing4 ,after fastening all of the wires their tension may be regulated by turning the nuts on the lower ends of the eye bolts4 ,it is very necessary that the frame should be perfectly true and not warped or twisted4 ,otherwise the machine will be very hard to balance and manage when making a glide4 ,especially must the rudder be true with the rest of the machine4 ,illustration3 ,fig4 #bd4--,method of anchoring wires ,since there are no eyebolts about the rudder which could be used to tighten or loosen the truss wires1 a turnbuckle must be included in each wire for that purpose4 99,turnbuckles499 ,the construction of these turnbuckles which are very simple and inexpensive is illustrated in ,fig4 #be4 ,they are made of a bicycle spoke and nipple by cutting off one end of the spoke and using the part which is threaded4 ,the end of this piece is bent back and twisted into an eye4 ,a piece of #a_/af inch sheet brass #a_/b x #c_/h inch has a hole bored in its centre1 the diameter of which is such that it will just admit the spoke nipple4 ,the nipple is prevented from passing all the way through by the shoulder on one end4 ,a piece of sheet iron #a_/b inch wide and #c inches long has a similar hole bored in its centre4 ,the ends of this strap are rounded and bored so that the piano wire may be passed through4 ,the turnbuckle is then assembled and connected as shown in the illustration4 ,the tension of the wire is regulated by turning the spoke nipple while the spoke itself is held rigid4 ,illustration3 ,fig4 #be4--;,bicycle spoke turnbuckle4 99,the second method99 of bracing illustrated in ,fig4 #bb requires that a turnbuckle be included in the diagonals of every rectangle1 except those formed by the stanchions with the horizontal beams4 ,this method is used on almost all aeroplanes and is considered the strongest but the first method is plenty strong enough for an ordinary glider4 ,if after trussing1 the machine is found to be warped or twisted1 it must be trued up4 ,by sighting along the horizontal beams and tightening or loosening the necessary wire any curvature may be easily corrected4 99,the second method99 of trussing is considerably harder to true up than the first1 since when one diagonal of a rectangle is tightened1 the other must be loosened4 ,but since it makes an exceedingly firm and rigid structure1 it may be well recommended to those who care to undergo the added expense and labor involved by the extra turnbuckles and wires4 99,to take the glider apart991 first remove the bolts holding the rudder beams in the sockets on the machine4 ,then unfasten the wires which brace the rudder to the machine by loosening the turnbuckles until the spokes and nipples unscrew and come apart4 ,the rudder may now be removed from the machine4 ,next take off all the nuts on the eye bolts in the lower plane and pull the eyebolts out of the sockets4 ,the two planes will then come apart4 ,remove the stanchions by pulling them out of the sockets4 ,the two planes are then laid one on top of the other and will occupy very little room4 ,,chapter ,,iv4 ,gliding4 ,the first words which may well be said upon this subject are to emphasize caution4 ,but by this ,i do not wish to imply that gliding is exceedingly dangerous4 ,neither do ,i by caution mean timidity but rather judgment and common sense4 ,canoeing is generally considered a safe sport1 but who would think of canoeing on the ocean in a storm4 ,it is exactly the same extreme to glide from a very high object1 or experiment in a high wind4 99,the atmosphere99 near the earth is a mass of whirling and swirling currents which are constantly rising and falling and become very pronounced in a high wind4 ,even in a comparative calm these eddy currents exist but of course not to a dangerous degree4 ,evidence of this may be seen by watching the little dust particles floating in the air and made visible by a sunbeam coming through the window of a quiet room4 ,although the sense of feeling cannot detect the smallest air current1 these little particles are whirling around and constantly changing their direction4 ,when the wind strikes some natural object such as a tree or a stone1 the streams of air divide1 part of them passing to the sides and part going over the top4 ,the air begins to divide some distance before it reaches the object and the result is a rising current on one side and a falling current on the other4 ,these currents are the bugbears of aviators for when one end of their machine passes into such a current that end rises or falls depending whether or not the current is rising or falling4 ,illustration3 ,fig4 #bf4--,top view1 showing how streams of air divide4 ,other rising and falling currents are caused by the sun passing behind clouds4 ,portions of the atmosphere are thus chilled and commence to fall while others upon which the sun is reappearing are heated and rise4 ,balloonists constantly encounter these changes in temperature and the gas in the bag expands or contracts so rapidly that it often requires a skillful pilot to prevent disaster4 ,these rising and falling currents caused by changes of temperature may be clearly seen on the surface of a lake if the observer is stationed at a height where he may look down on the water4 ,in some places the water is covered with smooth glassy streaks which run in various directions4 ,these smooth streaks are evidence of rising currents of air at those places4 ,the rough spots which suddenly spread out and run across the water are caused by descending currents4 ,therefore it is not good judgment to attempt gliding over ground broken by trees or other natural objects or when the wind is blowing over #ab-ae miles per hour4 ,illustration3 ,fig4 #bg4--,showing how air currents pass over objects4 ,do not under any consideration jump off from a height which rises prominently from surrounding objects4 ,otto ,lilienthal1 the brilliant ,german investigator and engineer who made over two thousand gliding flights specifically warned experimenters against starting glides from precipitous cliffs or buildings4 ,there are two excellent reasons for this4 ,first1 because when jumping from such an elevation1 a gust of wind rebounds from the sides and strikes the machine so that it requires great skill to counteract its influence4 ,second1 because1 the operator and machine are suddenly suspended high in the air4 ,be satisfied at first by running against the wind on level ground and making short jumps4 ,after some practice1 operations may be transferred to a gentle slope and the length of the glides considerably increased4 ,if the experimenter thus proceeds slowly without impatience1 there is no danger in gliding4 ,it is said that the ,wright brothers never so much as turned an ankle in the hundreds of flights they made1 before building a power driven machine4 ,illustration3 ,fig4 #bh--;,action of aeroplane4 99,action of an ,aeroplane994 ,before starting to glide it is perhaps well to understand how the machine operates and supports its passenger4 ,the illustration shows the cross section of an aeroplane moving forward through the air in the direction indicated by the arrow4 ,the front edge of the aeroplane is elevated so that the surfaces form an angle with the horizontal4 ,the front edge enters practically still air and causes it to follow the curve of the planes and leave at the rear in a downward direction4 ,since the action and reaction of two forces are always equal and opposite1 there is a force exerted against the aeroplane causing it to rise4 ,a sky-rocket is caused to ascend by the reaction of gases formed by burning powder escaping downwards through a small hole4 ,the aeroplane1 by means of its curvature directs the air downwards and so rises itself4 ,the planes pass so rapidly on to new and undisturbed bodies of air1 and stay over one body for so brief an instant1 that there is no time to completely overcome the inertia of the air and force it downwards4 ,this may be likened to a skater moving swiftly over very thin ice which would not bear his weight were he standing still1 but since he is moving so rapidly1 that any one portion of the ice does not have time to bend to the breaking point1 is supported4 99,equilibrium499 ,a glider will remain in perfect equilibrium only so long as the centre of gravity of the machine and operator fall in the same vertical line as the pressure exerted by the air4 ,if the former is forward of the latter1 the machine will incline forward and travel downwards4 ,if the centre of gravity is to the rear of the centre of upward thrust exerted by the air1 the head of the machine will rise1 while if it is to either the right or left side1 the machine will lean or turn over respectively to the right or left4 ,illustration3 ,fig4 #bi--,ready to ,start ,the centre of pressure on the plane is somewhat in advance of the actual dimensional centre of the plane4 ,this is due to the curvature of the plane and also to the disturbing action upon the air of the front edge4 99,to make a glide991 carry the machine to the top of a slope4 ,have two assistants hold the ends of the lower plane4 ,get in underneath and stand up between the arm pieces4 ,grasp the front horizontal beam of the lower plane and lift the machine until the arm sticks are snugly under the arm pits as in the illustration4 ,if necessary have the two assistants prepared to run a short distance with the machine1 but as soon as you are in motion you will be relieved of all weight and surprised at the lift exerted4 ,after getting the machine snugly up under the arm pits1 face the wind1 elevate the front of the machine slightly1 run a short1 distance and leap into the air4 ,if you are in the right position you will sail to the foot of the slope in free flight4 ,to land1 push yourself towards the back of the machine1 so that the glider tips upward slightly in front4 ,it will then rise slightly but loose its momentum and slowly settle so that you drop gently on your feet4 99,balancing99 is accomplished in flight by moving the legs and body towards that side which is highest4 ,illustration3 ,fig4 #cj--,lines of ,flight 99,shifting the centre of gravity99 by swinging1 the legs forward or moving the body in the same direction1 will naturally cause the centre of gravity to assume a forward position1 and being a force exerted downwards1 the machine will dip and descend4 ,a reverse movement of the centre of gravity will cause the front of the machine to tip up and ascend4 ,but if the upward slant is continued too long the glider will loose its forward velocity and settle4 ,the tendency is always to place the weight of the body too far to the rear4 ,after a little experience the experimenter will learn how to dip his machine to acquire velocity for a rise and to otherwise handle it4 ,fig4 #bi illustrates two lines of flight in their successive stages4 ,at #a the operator is running along the top of the hill and the dotted line from #a to #b represents his course immediately after leaving the ground4 ,in case the weight is back slightly too far and is not shifted much during the glide1 the machine will follow the upper line indicated by #c1 #d1 #e and land at #f4 ,if instead1 at #b1 the body is moved forward1 the machine will travel down as shown by #g and approach the earth4 ,having attained considerable velocity at ,s1 the operator moves back and the machine rises1 travels upwards as at #i and then settles about at the point #f4 ,this latter line of flight is to be preferred since the machine does not rise quite so high in the air and moreover has more velocity so that the operator may rise if necessary4 ,if during a flight a gust of wind strikes the machine from the front1 it will accelerate its vertical motion in regard to the earth4 ,that is1 if the machine is already rising it will rise higher and if descending will fall more quickly4 ,a gust of wind from the rear will cause the machine to drop suddenly and so always glide into the wind4 ,,chapter ,v4 ,remarks4 ,in a little booklet such as this it is even impossible to cover the subject of gliding flight fully much less power driven aeroplanes1 but a short description of such a machine built by the author1 assisted by ,mr4 ,harold ,dodd and ,mr4 ,safford ,adams will no doubt interest many since it has been used successfully as a glider in towed flights4 ,the machine was attached to an automobile by means of a long piano wire bridle4 ,it rises at a speed of between #ae and #bj miles per hour and remains in the air as long as the auto keeps moving at this rate4 ,the grounds used by the author in his experiments limited the flights to about #hjj feet4 ,the automobile in one flight traveled about #ej miles per hour1 but the machine soared on a perfectly even keel and without any pitching4 ,just as the author was about to descend1 the towing wire broke1 but the aeroplane glided so gently to the ground that it was impossible to tell where it first touched4 ,the following description of the machine is an extract from an article written by ,mr4 ,r4 ,s4 ,brown4 ,the two supporting surfaces of the aeroplane are five feet wide in the direction of flight and twenty six feet long4 ,when the machine is moved rapidly forward1 the action and reaction of the still air on the lower side of the moving surfaces1 lifts the aeroplane from the ground and supports it in the air4 ,the curvature of the planes is that segment of a parabola1 whose depth is one ninth its length4 ,they are spaced one vertically above the other and about four and one half feet apart in the middle4 ,the ends converge slightly to make the machine less affected by cross gusts4 ,the longitudinal curvature of the planes is maintained by spruce ribs half an inch square and spaced nine inches apart4 ,their front ends are ingeniously fastened in brass sockets on the front horizontal members and their rear ends project about a foot over the rear horizontal pieces4 ,the fabric a close woven muslin is put on over the top and bottom of the ribs and is fastened by grommets to a wire running through the rear ends of the ribs1 and by strips of felt fastened down to the ribs with upholsterer's tacks4 ,the stanchions are six feet apart except the middle two1 which are only eighteen inches apart4 ,the horizontal pieces of each surface are parallel and four feet distant from each other4 ,all are of selected spruce1 shaped so as to give the greatest strength with the least resistance to the air1 and the least weight4 ,all the many rectangles of the structure are braced diagonally with steel piano wire4 ,in every one a small turnbuckle is inserted to adjust the length4 ,the nuclei of these turnbuckles consists of bicycle spokes4 ,by this wiring a perfectly rigid truss is formed4 ,ten feet to the rear of the main body1 there is a horizontal tail1 which halves a vertical rudder of about the same area4 ,this vertical surface is movable and turns the aeroplane to the right and left when moved by rotation of the steering wheel4 ,as can be seen in the accompanying illustration these rudders are strongly supported from the principal structure4 ,at an equal distance in front of the supporting planes is the elevation rudder4 ,this consists of two horizontal plane surfaces1 six feet by two4 ,these turn about a horizontal axis transverse to the direction of flight4 ,thus the angle which they present to the wind can be altered at the will of the operator4 ,this is accomplished by pushing and pulling on the steering wheel4 ,through the middle of the horizontal surface runs a triangular vertical plane4 ,this is designed to prevent the turning of the machine by a gust striking the rear vertical rudder1 for if it strikes both vertical surfaces1 one in front and one behind1 the two neutralize each other and no turning takes place4 ,on the ground the machine runs on three twenty-inch pneumatic tired wheels4 ,these were especially made for the purpose1 with seamless rims and heavy motorcycle spokes4 ,two are set in regular forks of tubing under the rear edge of the lower plane1 while the third wheel is considerably in advance of the body proper4 ,when running on the ground preparatory to rising1 the machine is carried on these little wheels4 ,the operators seat is in front of the supporting planes1 and as the photograph shows is carried on two braces from the front wheel4 ,sitting in the seat1 the aviator can direct the aeroplane from side to side by turning the steering wheel before him4 ,this steering wheel is mounted on a post hinged at the bottom1 and by pushing or pulling on the wheel the aviator is enabled to control his height above ground by means of the elevation rudder which is connected by a wooden rod to the steering post4 ,mid-way between the two main surfaces and at the front of each end is a small plane4 ,these are tilted at positive and negative angles to the wind1 by means of cords connecting them with a pivoted bar moved by the pilots feet4 ,in flight1 if one end rises1 the aviator presses down the end of the bar on the rising side4 ,this causes the 'balancing plane' on the high side1 which is the name given to the movable planes just described1 to form a negative angle with the wind so that the high side is forced down4 ,the other balancing plane assumes an equal positive angle1 so as to force up the lower side4 ,thus the machine is again brought to an even keel4 ,after a little experience1 this action becomes almost automatic1 so that no difficulty is experienced in keeping the flyer level4 ,the motor1 which at present has not been installed1 will be supported between the two main planes and connected to a laminated spruce propeller1 six feet in diameter40 ,those who of until late have not been associated with aeronautics can scarcely realize the steps by which aviation had progressed and the trend towards building machines4 ,the aeroplane worker can no longer be classified with the seeker after perpetual motion4 ,it is therefore to be lamented that so many of these machines partake of freak construction4 ,originality is always to be fostered but must bear some degree of proportion4 ,only a very few favored people in comparison to the rest of civilization have been enabled to see an aeroplane in flight4 ,many times less are those who have had the privilege of examining a successful machine4 ,,books ,,for ,,aviators 99,,the ,,barometrical ,,determination ,,of ,,heights499 ,a practical method of barometrical leveling and hypsometry4 ,by ,f4 ,j4 ,b4 ,,cordeiro4 ,with an appendix on the ,air-,barometer4 ,full limp leather1 #a4jj4 99,,table ,,of ,,barometrical ,,heights ,,to #bj1jjj ,,feet499 ,computed by ,william ,h4 ,mackesy4 ,the tables are mainly intended for use with the compensated mountain aneroid barometer but they are also suitable for the mountain mercurial barometer4 ,a valuable little set of tables4 99,,the ,,atmosphere ,,its ,,characteristics ,,and ,,dynamics499 ,by ,f4 ,j4 ,b4 ,,cordeiro4 ,in producing this work the author has endeavored to place before the public valuable data and information collected by him as to the origin of hurricanes1 their causes and other atmospheric disturbances4 ,in view of the fact that so much interest is now being taken in the navigation of the air every scrap of information that can be collected relative to atmospheric conditions will prove of considerable value to all those interested in this new science4 ,the work is divided under the following headings3--,constitution4 ,temperature and density4 ,convective equilibrium4 ,various atmospheres4 ,aqueous vapor4 ,pressure of air4 ,practical barometry4 ,motion relative to the moving earth4 ,vertical motion4 ,horizontal motion4 ,frictionless motion over a rotating spheroid4 ,motion on the rotating earth without friction4 ,general circulation of the atmosphere4 ,equatorial circulation4 ,polar ,circulation4 ,middle circulation4 ,planetary circulation4 ,cyclones4 ,porto ,rican hurricane of ,august #h1 #ahii4 ,horizontal velocity4 ,tornadoes4 ,other ,phenomena occurring in the atmosphere4 ,sound4 ,merged explosions4 ,optical phenomena4 ,the rainbow4 ,atmospheric conditions in relation to flying machines1 etc4 ,with numerous tables and #cd illustrations1 #dto4 ,paper covers #a4ej1 full cloth1 #b4ej net4 99,,the ,,theory ,,and ,,practice ,,of ,,model ,,aeroplaning499 ,by ,v4 ,e4 ,johnson1 ,m4,a4 ,the object of this book is to give in plain language the general practice and principles of ,model ,aeroplaning4 ,model propellers and motors have been carefully dealt with1 and much valuable data included from the author's own experiments4 ,contents of ,chapters4--,glossary of ,terms used in ,model ,aeroplaning4 ,introduction4 ,the ,question of ,weight4 ,the ,question of ,resistance4 ,the ,question of ,balance4 ,motive ,power4 ,rubber ,motors and other forms of ,motors4 ,propellers or ,screws4 ,the ,question of ,sustention4 ,the center of pressure4 ,materials for ,aeroplane construction4 ,hints on the building of ,model ,aeroplanes4 ,the ,steering of the ,model4 ,the ,launching of the ,model4 ,helicopter ,models4 ,experimental records4 ,model ,flying competitions4 ,useful notes1 tables1 formulae1 etc41 etc4 #afc pages1 #hb illustrations1 #abmo cloth1 #a4ej4 ,,books ,,on ,,aeronautics4 99,,resistance ,,of ,,air ,,and ,,the ,,question ,,of ,,flying499 ,by ,a4 ,samuelson4 ,an important lecture of considerable interest to those interested in ,aeronautics4 ,contents3 ,introduction4 ,the ,resistance of ,plastic ,bodies4 ,air-pressure on ,flat ,bodies4 ,the ,centre of ,air-pressure4 ,distribution of the ,air-pressure on the ,single ,elements of an ,inclined ,plane4 ,the ,normal ,air-pressure on a ,thin ,plane ,inclined at an ,angle to the ,direction of ,motion4 ,lilienthal's ,balance of ,rotation4 ,the ,numerical ,value of the ,normal ,pressure4 ,flying in ,general4 ,flying in ,reality4 ,horizontal ,flight by ,wing-,flapping4 ,steering and other ,effects of the ,stroke4 ,conclusions4 99#bc illustrations1 #hvo41 paper4 #ge;c499 99,,flight-,,velocity499 ,by ,a4 ,samuelson4 ,this work is a short comprehension of extensive scientific investigation and experimental work4 ,contents3 ,the ,rowing ,flyer ,no4 #e4 ,the ,motor ,mechanism4 ,the ,fundamental ,conditions of ,flying by ,wing ,flapping4 ,the ,wings4 ,the ,re-sail4 ,flight ,velocity4 ,living ,flyers4 ,plane or ,concave ,supporting ,surfaces4 ,the ,false ,resolution of ,forces4 ,the ,erroneous ,opinion3 the ,breadth of an ,incline ,plane ,prevails over its ,length4 ,the ,centre of ,air-pressure1 and the ,distribution of the ,pressure4 ,on the ,single ,parts of an ,inclined ,plane4 ,the ,principle3 the ,normal ,air-pressure of an ,inclined ,plane is independent of the ,angle of ,inclination4 ,tables of ,motion at ,varying ,angles4 ,the ,human ,flight4 ,conclusions4 99,with five plates1 #hvo41 paper4 #ge;c499 99,,flying ,,machines499 ,past1 ,present and ,future4 ,a popular account of flying machines1 dirigible balloons4 ,by ,a4 ,w4 ,marshall and ,h4 ,greenly4 ,whilst the matter in this book is intended as a popular exhibition of the subject1 it includes information which will assist the reader with serious intentions of making an attempt to produce a flying machine or air-ship4 ,a great deal of sound experimental work has been done1 forming a basis upon which future plans can be calculated4 ,an account of some of this work is here given4 ,contents of ,chapters3 #a4 ,introduction4 ,dr4 ,barton's ,air-ship4 ,lebaudy's ,military ,air-ship4 ,the ,deutsch ,air-ship4 ,the ,wellman ,air-ship4 ,motors of the ,wellman ,air-ship4 ,chapter #b4 ,dirigible ,balloons4 ,giffard's4 ,dupuy de ,lome4 ,tissandiers'4 ,krebes'4 ,santos ,dumont's1 ,no4 #f and ,no4 #i4 ,spencer's ,air-ship4 ,barton's4 ,maxim's ,flying ,machine4 ,archdeacon's ,air ,propeller ,cycle4 ,barton's1 ,rawson's1 ,baulx1 ,zeppelin1 ,deutsch1 ,lambert1 ,wellman's ,air-ships4 ,trolanini's ,air-propelled ,boat4 ,chapter #c4 ,flying ,machines4 ,giving a ,number of those made by ,hargrave and also by ,phillips1 ,ader1 ,maxim1 ,pilsher's ,soaring ,wings1 ,langley1 ,bastine1 ,bleirot1 ,voison1 ,wright's ,gliding ,aeroplane1 and numerous others4 ,chapter #d4 ,the ,art of ,flying4 ,chapter #e4 ,flying ,machines of the ,future4 99#acd pages1 illustrations and page plates1 #abmo4 #ej;c499 ,,model ,,aeroplanes4 99,,model ,,flying ,,machines1 ,,their ,,design ,,and ,,construction499 ,by ,w4 ,g4 ,aston4 ,contents of chapters3--#a4 ,general principles and their application4 #b4 ,power4 #c4 ,supporting surfaces4 #d4 ,screws1 and how to make them4 #e4 ,tails and elevators4 #f4 ,fins4 #g4 ,designs4 ,with a number of examples of monoplane1 bi-plane1 tandem bi-plane and tri-plane models4 #h4 ,dirigibles4 #i4 ,helicopters4 #aj4 ,ornithopters4 #aa4 ,winding apparatus4 #ab4 ,compressed air motor4 ,a first-rate book for ,model ,makers1 #abe pages1 #ie illustrations1 #abmo4 boards1 postpaid1 for #ee;c4 99,,model ,,gliders1 ,,birds1 ,,butterflies ,,and ,,aeroplanes499 ,how to ,make and ,fly ,them4 ,a booklet with one large sheet containing twelve butterflies and two birds in colors and material for making a small card-board ,model ,aeroplane ,glider4 ,complete in folder1 postpaid1 for #ee;c4 99,,model ,,aeroplanes1 ,,how ,,to ,,build ,,and ,,fly ,,them499 ,by ,e4 ,w4 ,twining4 ,consisting of one booklet and five large scaled drawings for three ,twining ,models1 two of them being of the ,bi-plane ,glider type4 ,complete in folder1 postpaid1 for #ee;c4 99,,twining',s ,,model ,,no4 #b499 ,a complete set of the materials in the rough1 including the rubber of a ,bi-plane ,model without the drawings1 postpaid1 for #fe;c4 99,,twining',s ,,model ,,no4 #c499 ,a complete set of materials in the rough with rubber for the construction of this handsome ,model ,bi-plane without the drawings1 postpaid1 for #a4ae4 99,,the ,,aeroplane ,,portfolio499 ,by ,d4 ,ross ,kennedy4 ,containing nine sheets of scale drawings of the following celebrated ,aeroplanes3 ,bi-plane type--,wright1 ,farman1 ,voisin1 ,cody1 ,herring-,curtis4 ,monoplanes--,rep4 ,antoinette1 ,santos ,dumont1 and ,bleriot4 ,each of these machines are here shown in ,end ,view1 ,plan and ,elevation4 ,including booklet which contains a description of each machine4 ,this timely set of drawings should prove of value to everyone interested in this important new industry4 ,the complete set in folder1 postpaid1 for #ee;c4 99,,the ,,percy ,,pierce ,,flyer499 ,a large scale drawing of this prize-winning ,monoplane4 ,with all measurements and details showing a front elevation1 a side elevation and a top elevation2 with #h-page descriptive booklet of particulars postpaid1 #ae;c4 99,,percy ,,pierce ,,drawing199 with booklet and complete set of materials in the rough from which any one can make an exact duplicate of this dandy ,model complete1 postpaid1 for #a4ae4 99,a ,,three-,,foot ,,model ,,aeroplane499 ,bleriot ,type4 ,by ,g4 ,e4 ,alexander4 ,a large scale drawing with measurements and descriptive matter showing the construction of a splendid ,model ,flying ,machine4 ,the ,model from which this drawing is taken has proved a very successful flyer1 postpaid for #ae;c4 ,,good ,,books ,,for ,,wireless ,,operators4 ,,part ,i4 ,,plans ,,and ,,specifications ,,for ,,wireless ,,telegraph ,,sets1 ,complete and ,detailed ,instruction for ,making an ,experimental ,set1 also a ,one to ,five ,mile ,set1 #ee pages1 #cg illustrations2 price #be;c4 ,part #b4 ,,plans ,,and ,,specifications ,,for ,,wireless ,,telegraph ,,sets4 ,by ,a4 ,frederick ,collins4 ,will contain complete and detailed data for constructing a ,five to ,ten ,mile ,set1 also a ,ten to ,twenty-five ,mile ,set1 with about #fj illustrations1 and #ij pages4 ,price1 #be;c4 ,parts three and four in preparation4 ,,making ,,wireless ,,outfits4 ,by ,newton ,harrison4 ,a concise and simple explanation on the construction and use of simple and inexpensive wireless equipments1 for sending and receiving1 giving full details and drawings of apparatus1 diagrams of circuits and tables4 ,including the ,morse and ,continental ,codes4 #fa pages1 #bg illustrations4 ,price1 #be;c42 cloth1 #ej;c4 ,,wireless ,,telephone ,,construction4 ,by ,newton ,harrison4 ,a comprehensive explanation of the making of a ,wireless ,telephone ,equipment4 ,both the transmitting and receiving stations fully explained with details of construction sufficient to give an intelligent reader a good start in building a ,wireless ,telephone system and in operating it4 #gd pages and #dc illustrations4 ,price1 #be;c4 ,,telegraphy ,,for ,,beginners4 ,the ,standard ,method4 ,an authoritative book of instruction in the methods and forms most approved1 with a series of lessons4 ,by ,willis ,h4 ,jones4 ,with the ,morse alphabet and the ,continental code4 #fd pages1 #ai illustrations1 paper binding1 #be;c42 cloth binding1 #ej;c4 ,,induction ,,coils4 ,how to ,make and ,use ,them4 ,by ,p4 ,marshall4 ,a practical handbook on the construction and use of sparking coils for wireless telegraphy4 ,with tables of windings for coils giving #a_/d in4 spark up to #ab in4 sparks4 ,with full description for the construction of mercury interrupters4 #gf pages1 #ce illustrations4 ,price1 #be;c42 cloth binding1 #ej;c4 ,full descriptive circular of ,the ,model ,library ,series of practical ,handbooks ,,free4