Set of documents Edgar Allen & Co of Sheffield promoting and providing information about the Woods Gilbet Rail Planing machine. 1 - letter dated June 1917, sent from the South Australian Hotel in Adelaide to Mr Pringle, of ESCo from the travelling representative of the company, a letter on Edgar Allen & Co letterhead with a list of various articles on the machine, and a letter from Woods Gilbert of their Melbourne office, dated Jan. 1917 2 - A 30 page printed booklet contained within a green cover titled "Rail Planing Machines" with Mr Pringle's name written on it in the top right-hand corner. 3 - Photograph of the rail planing machine with "1916 type rail grinding machine" on rear in pencil along with the Company stamp. 4 - Drawing of the Milling Trolley prepared by Atlas Co of Engineers Melbourne 5 - drawing - Cardiff-rail-section Woods-Gilbert 6 - photograph - Woods-Gilbert Recording instrument on a postcard by Kodak Magazine extracts: 7 - Woods-Gilbert Tramway and Railway World-12 Oct 1916 - page 1 of 2 8 - Woods-Gilbert Tramway and Railway World 12 Oct 1916 - page 2 of 2 9 - Woods-Gilbert Tramway and Railway World Nov 1916 - page 1 of 2 10 - Woods-Gilbert Tramway and Railway World Nov 1916 - page 1 of 2 11 - Woods-Gilbert Tramway and Railway World - 12 Apr 1917 page 1 of 2 12 - WoodsGilbert Tramway and Railway World - 12 Apr 1917 page 2 of 2Yields information about the Woods Gilbert Rail planing machines for repair of rails and removal of corrugations.Set of 12 documents with letters, pamphlet, photo, drawing and magazine cuttings.tramways, trams, esco, rail planing, woods - gilbert, track, rails, tramway rails, maintenance equipment

The Mark II Pilot Balloon Slide Rule was made of wood laminated with heavy white plastic with a length of 24.5-in. and width of 2.5 inches. Mark II rules were manufactured in Australia by W & G (Melbourne). The W & G rule differs only slightly from the English A. G. Thornton LTD rule. The W & G rule uses serif fonts and has some fiducial marks that the English rule lacks. Exact dates of production are not known but the MK II is known to have started production by 1927. The printed scales are engraved in the plastic faces. The slide rule has 4 captive cursors (glass windows and brass guides) that ride in slots on the top and bottom edges. Each can be moved independently of one another. The cursors are missing from this item. Brass knobs at both ends of the slide facilitate its movement. The case is fabric covered wood with felt lining. No known history for this item as located in a property after purchase. The Pilot Balloon slide rule is used to convert the observed azimuth and elevation readings into wind velocity and direction records. The use of slide rules was abandoned with the wide spread adoption of computers and programs to do the calculations, as well as the decline in the use of optical pilot balloon theodolites.Made in Australia by White & Gillespie (Melb) Pty Ltd. Established in 1910, the firm was involved mainly in printing plate manufacture, but during the Second World War it manufactured a variety of navigational aids and range finding devices for the military. About 250,000 instruments were made during that period. After the war the company produced, among other items, drawing instruments and slide rules. The long narrow case is fabric covered wood with felt fabric lining containing a long black laminate ruler with numerous white markings and numbers. Top of the ruler is in three sections with the centre section movable by small gold metal knobs at either end. This slide rule contains a engraved notation on the rear face "IMPORTANT. NORMALLY NUMBER OF GRATICULE SCALE DIVISIONS PER RADIAN (K) X LENGTH OF TAIL IN FEET (I) = 12X 105. IN OTHER CASES MULTIPLY GRATICULE READINGS BY 1.2/KI BEFORE CALCULATION ON RULE" Top of Slide Rule - RAAF Ident No G268/480 Serial WG/22pilot balloon slide rule, raaf