Set of 13 tuning forks tuned to each semitone of the musical scale, based on C4=256 Hertz (A4=435 Hertz); each with spherical brass knob on end; all enclosed in a hinged wooden case. Wooden clamp for forks included in the box. Performance certificate available. 53.1=box 53.2=wooden forks clamp 53.3-53-15 =13 tuning forks.Engraved plaque inside box: International Stimmunt ut 3-517,304v? 1a 3-870v?; C1-258,652 Schwingungen a1-435 Schwingungen. Inscribed on top of box Max Kohl Chemnitz 1/5 Label on side of box:Tuning forks. On each tuning fork size is identified as MK inscribed.

2 slides (54.1 & 54.2) wrapped in paper and stored in a small hinged metal chemist’s pill box (54.3). ;Also an unidentified 8.5 cm (graphite?) stick (54.4) Slide 54.1 is wrapped in paper and identified as “very precious”. On the slide is printed: ONE INCH divided into hundredths. In ink: “Dup. Beck. Retain.” Next: 1-14 in. cover glass. Then printed: Ruled on glass. H.J. Grayson. No. 2 Slide 54.2 is also wrapped in paper. Ruling can be seen under 3/4 iin. cover glass. Carries labels: “760 or 1/60 xxxx” and “60,000 # good”. On the wrapping paper: “Grayson Test Ruling, given to me by the late Mr W Stone.” Signed: W.M. Holmes, 18.9.50 In differnet penmanship: “Labelled 60,000 gtooves #. White sticker with red bars. Placed in display cabinet 13.8.71 J J McNeill.(All this transcription by EGM)Label On 54.1: “One inc divide into hundredths Dup Beck Retain. Ruled on glass H.J. Grayson No.2” Labels on 54.2: “60”, “60,000# good”. Label on box (54.3): “Grayson Test Rulings 60,000 from W.A. Holmes, Balmoral Ave, Kew”. On metal stick (54.5): “S.F.342” (Prior description by Anna)

Part of a series entitled “Optical Munitions - School of Natural Philosophy, 1942-1945”. Black and white photo of Fred Caldwell looking through instrument.In ink on lower left hand corner : “12”

Part of a series entitled “Optical Munitions - School of Natural Philosophy, 1942-1945”. Black and white photo of V.D. Hopper in experimental mode (with stop watch and potentiometer). In ink on lower left hand corner : “13”

Part of a series entitled “Optical Munitions - School of Natural Philosophy, 1942-1945”. Black and white photo of J.F.G. Darby (Left) & W.B. Lasich (Right) sighting on apparatus(??).In ink on lower left hand corner : “11”.

Part of a series entitled “Optical Munitions - School of Natural Philosophy, 1942-1945”. Black and white photo of L.H. Martin with ?? apparatus (possibly gun sight).In ink on lower left hand corner : “10”.

Part of a series entitled “Optical Munitions - School of Natural Philosophy, 1942-1945”. Black and white photo of “Peter Law (Left) & A.C. Goodwin (Right)”. Involved with optical flats in aluminising apparatus.In ink on lower left hand corner : “9”.

Part of a series entitled “Optical Munitions - School of Natural Philosophy, 1942-1945”. Black and white photo of “Peter Law (Left) & A.C. Goodwin (Right)”. Involved with optical flats in aluminising apparatus.In ink on lower left hand corner : “8”.

Part of a series entitled “Optical Munitions - School of Natural Philosophy, 1942-1945”. Black and white photo of Geo Armitage testing a monocular (or part of the binocular testing program?). Same apparatus as in no 134. In ink on lower left hand corner : “7”.

Part of a series entitled “Optical Munitions - School of Natural Philosophy, 1942-1945”. Black and white photo of Henri Rathgeber operating Michelson Interferometer.In ink on lower left hand corner : “6”.

Olive green enamelled stereoscope enclosed in olive green wooden hinged box. Two test stereoscopic pictures of a rhino also kept in box. A wooden oddment (10 cm) is also enclosed.Engraved in white on stereoscope: “DC-1940 Serial No. 32” Label on front of box: “stereoscope”

Student Potentiometer (Type D-73-E) set in wooden box with lid. Black control panel with various dials:two for VOLTS & MILLI-VOLTS; others for galvanometer sensitivity, battery rheostats, etc. 24.1 = potentiometer 24.2 = lidPlaque on front of box: “J.L.William Scientific Instruments Serial No. 1480. Type D-73-E Melbourne Australia”. Inscribed on control panel: “J.L.William Scientific Instruments Melbourne Australia. Various control panel markings.

Planimeter consisting of brass disc and measuring instrument made of white disc and attached bar. To measure area up to about the size of one A4 page. The instrument is stored in a black hinged box with purple velvet lining and small metal catches. Instruments instructions are attached to a label on the inside of the case. A small key is attached to the case lid by string. (23.1 = box, 23.2 = brass disc, 23.3 = planimeter)On planimeter (23.3): “G.Coradi Zurich Switzerland No. 3509” On box (23.1): “Nat. Phil. Lab. No. 1199, Gebr Wichmann Berlin”

Copper magnetron with disc-like body has three radiating electrodes each emerging through a copper to glass tube. Two of these are arranged on one side(= filament leads) and the other larger tube (collector/anode) is arranged diametrically opposite.Handwriting on top “?A4 A98/4.9%”

3 cm dia oxidised copper cylinder held in construction jig (consisting of two flat square steel slabs clamped with bolts). Three copper through glass electrodes radiate out from the magnetron cylinder. Two of these tubes are small and adjacent to each other (filament leads).

Copper cylinder to which radial copper vanes are brazed defining twelve resonant cavities. Central cylindrical cavity contains white oxide coated cathode sandwiched between two stainless steel disks, one at each end. Three electrodes pass through glass-copper seals, the copper tubes are attached radially to the outside of the cylinder.

Chrome cylindrical neutron counter. Length approx. 1 m.“H7100 - 700246” painted on inside end of tube.

Glass Geiger counter ready for evacuation. For details see No 15.

Cylindrical glass Geiger counter tube, inner surface (cathode) partially covered in evaporated gold.“IE29”

Black cylindrical galvanometer with circular base standing on three legs.Embossed: “Leeds and Northrop Co. Philadelphia PA”, “652978”, “Zero Adjuster/Coil Clamp”. Labels: “Part 2”, “Supplied by A.W. Dodds Pty Ltd, 612 Collins Street, Melbourne MU 6786”

7 flat discs (battery like) with diffraction gratings (55.1-55.7). surface rectangular rulings extend mostly 15mm . stored in specially converted metal hinged cigarette box (55.8) with wooden compartments

Clear glass tube, about 50 % completed by glass blower towards Geiger counter construction.

Short glass Geiger counter tube with evaporated gold cathode.

As for Cat. 58 demonstrating GM Tube prior to evaporation of cathode.

Boron Triflouride neutron proportional counter. Long glass tube covered in black enamelCello taped label: “20th Century Electronics” “Type G.60 Operate at 1250 Volts No. KK854” “Made in England”

Glass donut with injector arm and attached wires. Internal surface is sand blasted and silver plated. Mounted on specially made demonstration stand. Reg 269.6 is photographs of the object.Plaque on mould: “Glass Donut for 2.8 MEV Betatron W.B.Laish and L.Riddiford 1946”

Certificate of Examination for #64 of one 6 inch glass scale, one 6 inch steel scale, and one 6 inch end gauge for Professor Lyle. 3 page document (copy) from National Physical Laboratory, Teddington. Paper held together with pin. (See also #63)

U.S. Bureau of Standards Certificates for #65 for 6 inch steel scale, 6 inch steel end measuring rod, 6 inch glass scale. Three Department of Commerce Bureau of Standards certificates submitted by Professor Lyle for scales made by H.J. Grayson. Held together by paper clip. (See also #62)

(1) Glass rectangular scale (1-(1)-6 inch); (2)ditto steel rectangular scale, (3) ditto metal cylindrical rod. Enclosed in black hinged box with purple velvet lining. 64.1 = steel scale, 64.2 = glass scale, 64.3=steel rod, 64.4 = box. See#62 “National Physical Laboratory Certified Standards”On top of box labels: “Length Standards 3BA”, “National Physical Certified Standards 1.6 inch steel scale. 1.6 inch glass scale, 1.6 inch rod. For particular see certificate 1915” “40 6”. On glass scale engraved: “13.0 cNP” Engraved on steel scale “H.J.G. Melb Univ. 1915 ruled at 12.9 Celsius” . On glass scale engraved: “H.J.G. Melb Univ. 1915” “1,2,3,4,5,6”. (H,J,G, = Henry Grayson)