Slide rule for determining concentration of gas at a given range, housed in leather carry case. Manufacturer unknown (likely military). Date of manufacture unknown (possibly circa World War Two).

Slide is marked on front: "Rule, Slide, Gas-Concentration-Range. No. B45".

Three instructional plates affixed to reverse:
No. For HCE [hexachloroethane] smoke
Source strength to produce a given concentration
Ground Roughness Corrections.

Metal assembly with accompanying note in Peter Dunn's handwriting:

"Suspension lug assembly from a 250lb chemical bomb recovered at Majnoon Island - Iran - March 1984. Mustard gas residues were found on the lug thread. Filling hole also present."

(Suspension lugs are used to attach bombs to an aircraft's suspension and releasing equipment.)

Item repackaged into acid free materials during archival processing.

Metal fragment with accompanying note in Peter Dunn's handwriting:

"Average thickness 2.15mm."

This item is presumed to be a bomb casing sample.

Item repackaged into acid free materials during archival processing.

Glass lens with accompanying note in Peter Dunn's handwriting:

"Aircraft camera lens developed in the 1950s at DSL [Defence Science Laboratory], Maribyrnong. The key was a new lens adhesive based on special methacrylate resin systems developed by Peter Dunn and others. Repacked 1999."

The numerals 331-1 are etched into the side of the lens.

Item repackaged into acid free materials during archival processing.

Various items as follows: three pieces of metal shrapnel; one intact metal object [presumably bomb related]; two plastic objects housed in an envelope inscribed "Tefzel samples" in Peter Dunn's handwriting.

Tefzel® is a modified copolymer of tetrafluoroethylene and ethylene. It provides high resistance to attack by chemicals and solvents, and has excellent mechanical strength, stiffness, and abrasion resistance. It also has low dielectric constant and uniform electrical properties.

Items repackaged into acid free materials during archival processing.

Three pieces of melted plastic, significance unknown.

Items repackaged into acid free materials during archival processing.

A child's gas mask, housed in original cardboard box. Includes pamphlet dated July 1939: "Anti-Gas Protection of Babies and Small Children"; issued by the Air Raid Precautions Department of the British Home Office.

The respirator is of metal, rubber and fabric construction, with some minor signs of age deterioration to the rubber elements. The metal filter container is embossed "G.C. MK.III.". The rubber is imprinted with the number 15 near the upper edge of the face mask and on the expiratory outlet valve bears the following printed stamps: "Lot 101"; "4/41"; "P.B.C."

An intact Fuller Calculator (spiral slide rule) featuring bakelite handle and ends, brass pointer and fittings, and dual cylinders showing data tables and calculation measures. Housed in orginal mahogany case, with labels affixed inside lid. Approximate measurements: 45cm length x 10cm diameter. Made in England by W.F. Stanley & Co. Serial number: 13093 65.

Three labels affixed inside the lid of the wooden box relate to manufacture (W.F. Stanley & Co. Ltd, London); sales (N.H. Seward Pty. Ltd, Melbourne); and care of the instrument. A further label is affixed to the calculator: "Department of Supply. Plant # DSLM 10578".

Instructions on the use of the Fuller calculator are also extant in the Dunn Collection. See Inventory Item DUNN00871 Instructions for the use of the [Fuller Calculator], in Series 17 - Published Documents Including Materials Research Laboratory Reports.