Grey metal boxed navigational computer, hinged lid with notebook attachedUnder metal lid inscribed 'Navigational Computer MK. 111 D. REF. 6B/180'16 On note pad Dalton 'Air Navigation Computer, as used by Flt Lt F.P. Field Aus 4o1817 1941,46. On operations over Atlantic Ocean on 'short' Sunderland 4 engine flying boats.

The navigational computer was a circular slide rule used for calculating height and air speed corrections when flying an aircraft. The front cover lifts to reveal a further calculator used to solve vector triangles and plot course alterations. The device was intended to be strapped to a pilot's leg. The instrument was made by White and Gillespie (Melbourne) Pty Ltd c 1940 for the RAAF and used during WW2.Black metal box with silver metal flap top cover affixed with rotating circular rule . Two adjustable belts are affixed to the base of black box. A small spiral bound note book is contained beneath the flap top. RAAF Computer Navigational system MK. III. D. Serial No WG 2833navigation, raaf, computer, aircraft, ww2, 1940

Used by RAF and RAAF during WWII Believed to have been used in the battle of britainMetal faced bakelite box with rotating dial on front and a paper graph sheet enclosed in front cover a pencil for plotting course and position is attached to the side of the unitNavigational Computer ICANican computer, battle of britian computer, aircraft computer, mechanical computer

This type of instrument typically used by pilots and navigators for quick calculations of Air Speed and Wind Drift.hand operated navigation computer. Rotating scale on the front panel and a scroll type scale on the inner panel with a winder knob on the right side. Front panel is hinged at the top and bottom has two curved thigh pads.Indent No. G6B/145 RAAF Serial No. WG/2967* I.C.A.N. in center of front dial COMPUTER NAVIGATIONAL Ml. III D.

Used by RAF during WWIIMetal calculator with rotating metal dial and slide scalewith additional rotating ial on revrseCalculateur D'Estime A.A.F. Type 40navigation computer, aircraft computer, air force course computer,

Slide Rule type navigation computer. Stainless steel/plastic. Uses dead reckoningRAAF Indent no. G6B/2087 Serial no. WG/442royal australian air force, navigation

Item used by Navigators or Pilots of small aircraft. Belonged to Maxwell Lennox MATHESON 418447 RAAF. Refer Cat No1959 for his service history.NAVIGATIONAL Computer Mark III.D, metal - bakelite, construction rectangular box shape, top lid hinges open. Top lid has a circular adjustment. Inside has another circular adjustment. Centre is a graph in red which winds by a dial on side. Inside top lid hand written in black are items of Navigation."NAVIGATIONAL Computer MKIID REF No 68/180 ICAN CALIBRATION"electrical technology, appliances & accessories, navigational

WWII Historical significanceRAAF Navigational computer MK111 D used in WW11 in aircraft for plotting direction and wind speed with original box.Identification number G6B/145. Serial No WG/2677*. Contains original pencil from 1940 and navigational notebook.

RAAF Manual navigation aircraft calculator(early computer)General issue to allied pilots and navigators for airspeed,altitude,air temperature and drift calculations.Black metal box with SS flap-top cover, moulding and straps for knee attachment.Engraving No. 19, Ident.No. G6B/145. I.C.A.N. Serial No. WG/1716*. Computer Navigational Mk.IIID

Metal slide rule type calculator, with scrolling graph. Has pencil/pen saddle and clip on left sideNavigational Computer Mk. IIIH Reg No. 68/250 Front. True Course, drift port Drift stbd Rear. I.C.A.N. Calibration, height correction, air speed correction

Rectangular calculating instrument with (1) 'hinged lid' fitted with circular rotating dial for setting/reading altitude, speed, distance and temperature, (2) notebook inside lid, (3) circular dial with perspex cover, beneath which is (4) graph chart, moveable up-and-down by means of rotating knob on side of device. Curved brackets and elasticized straps on back for strapping onto pilot's leg.R.A.A.F. Ident. No. G6B/145 Serial No. WG/2233 COMPUTER NAVIGATIONAL Mk. III D. (Other inscriptions including instructions for use and scales for various measurements) "AB" hand written on strap (owner's initials?)

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