Accession No

3268

Brief Description

automatic quartz spectrograph, ‘Barfit’ model, by Adam Hilger Ltd., English, c. 1948, and Judd Lewis spectrum comparator, by Adam Hilger Ltd., c. 1948

Origin

England; [Camden Road; London N.W.1]

Maker

Adam Hilger Ltd. Hilger and Watts Ltd.

Class

optical

Earliest Date

1935

Latest Date

1960

Inscription Date

Material

metal (white metal, stainless steel, brass, at least 2 other types); hide (leather); cloth (2 types); wood (?)

Dimensions

one part length 2190mm; breadth 500mm; height 465mm; Spectrum comparator (on floor) breadth 350mm; height 430mm; depth 355mm; 3rd part length 270mm; breadth 285mm; height 275mm; accessory rails each length 1180mm; breadth 66; height (with feet) 67mm; accessory drawer length 505mm; breadth 415mm; height 330mm

Special Collection

Provenance

Transferred from Department of Earth Sciences, University of Cambridge, Cambridge, England, 09/1985.

Inscription

‘ADAM HILGER LTD
LONDON
MADE IN ENGLAND
NO E478303
47241’ (on top of instrument)
‘ADAM HILGER LTD LONDON.
THE WORDS
BARFIT.
ARE REGD. IN.
GREAT BRITAIN. 568.606
U.S.A. 345.762.’ (white metal plaque on 2nd part)
‘ADAM HILGER LTD LONDON ENGLAND’ (on each accessory rail)
‘ADAM HILGER LTD LONDON ENGLAND’ (on both sides of spectrum comparator)
‘HILGER
&
WATTS
H 698.304
61583
MADE IN ENGLAND’ (white metal plaque on base of rotating stepped sector)

Description Notes

Hilger ‘large fully automatic quartz spectrograph’. Grey-green painted metal casing with iron base and 3 feet. Position for accessory bar (2 bars extant). Casing completely conceals optical parts. Slit position at side of instrument (no slit in place) with scale divided 0 - 5. Large knob with worm operates rack and pinion adjustment at front for adjustment of wavelength range with drum displaying range. Drum has scales for right end and left end. Right end scale divided 22.4 - 80. Left end scale divided 19 - 32. Both variously numbered and subdivided. Also large knob with worm operating rod which turns inside instrument. Photographic plate fixed to instrument with leather bellows, hinged at one side. Handle for adjusting height of photographic plate with. Plate moves against scale divided 0 - [75] (mm) numbered by 9, subdivided to 3. Also inclination screw for plate with scale divided 0 - 30 numbered by 10 subdivided to 2. Accessory rails are grey/green painted iron or white metal rail with rubber feet (one foot missing on one rail, both missing on other). One rail has piece of insulated electrical wire attached to underside. Another part associated with the spectrograph consists of a grey-green arched cover with one long foot and tower. The top of the tower has a flat plate for mounting accessory. Plate has 3 holes and 2 locating pins.

A grey-green painted metal frame of semi-circular cross-section forms the stage of the spectrum comparator. Lateral adjustment for spectrum plates. Supported over the stage are 2 white metal rails on which move the optical system. The optical system consists of 2 object glasses, a prism system and a single push-fit eyepice, all housed in a black-painted and textured metal casing. Also moving with this system is a (standard type) bayonet-mount electric lamp, and 2 mirrors, used for illuminating the spectra. A cloth covered flex runs from bulb mount to plastic switch, and a flex runs from switch to a 3-pin plug. Black cloth associated with the object may be for light proofing (no obvious means of attachment to instrument)

Drawer of accessories contains:

1. Condenser lens (no. H.438.301/47274) on swinging arm on ‘raising and lowering’ Barfit stand.

2. Mirror on rainsing and lowering Barfit stand. Clamping screw and ajustment screw missing.

3. Condenser on raising and lowering Barfit stand. This carries a handwritten label reading ‘Focussed on prism 5cm from slit’ and a white metal plaque bearing the number ‘F1083’.

4. Adjustable slit on rasing and lowering Barfit stand. This has a white metal plaque on base, bearing the number ‘F1083’.

5. Gramont arc and spark stand on Barfit stand (serial number F.946.304 / 47715). This comprises 2 clamps to hold rods (eg carbon rods for arc lamp) on arms mounted on white metal column. The arms have terminals part way along their length. The upper arm is adjustable by a rack and pinion operated by knurled screw. This enables adjustment of the arc or spark gap while running. The lower arm has clamping screw and can be adjusted manually. The central column can be raised or lowered by means of a rack and pinion operated by knurled screw. This enables adjustment of the height of arc or spark while running. Parts of carbon rods stillin place.

6. Rotating stepped sector on grey-green painted Barfit stand (Hilger and Watts no H 698.304/61583). This comprises a black painted(?) metal disc whose circumference is cut into a number of steps of equal depth, the angular lengths of which are in the ratio 2 to 1. The disc rotates in front of a condenser lens, located at the top. On the opposite side of the housing to the disc is a transformer and (presumably) a motor to drive the disc. A cloth covered flex leads from a 2 pin plug to terminals near the transformer (these terminals may have originally been protected by a black plastic casing, now broken).

(The Barfit stand is the base with the correct mounting to fit on the accessory bar of the Barfit model spectrographs. Except as specified above, they have black-painted and textured bases and white metal columns and a white metal knurled screw for clamping on to the bar and a white metal knurled screw for loosening central column and enabling vertical adjustment.)

7. Black-painted and textured metal negative holder with metal dark slide and white metal strips for retaining front cover.

8. Cardboard box with handwritten marking ‘2 slits / Spectrograph E478’ containing 2 slits in protective padding. One numbered ‘F.1386’ and marked ‘0-0.1 mm. 1 div. = .001 mm with micrometer screw divided 0 - [0.05] (mm) numbered by 0.01 subdivided to 0.001, reading against scale with ‘0’ marked and divisions for 0.05mm, 0.1mm and 1mm. A white metal knurled screw rotates a slide which combines three-aperture and reducing diaphragms. A window below indicates which aperture is in use with the three apertures numbered 1-3 and the reducing diaphragm showing slit height, numbered (millimetres) 18 and then 9 - 0 numbered by 1. A white metal lever operates an internal shutter. Complete with screws for mounting onto spectrograph. Second slit in black-painted brass housing marked ‘1 div = .005 mm.’ with micrometer screw divided 0 - [50] (mm) numbered by 5 subdivided to 1 reading against scale divided 0 - [2.5] (mm) numbered by 1 subdivided to 0.25. Three-aperture and reducing diaphragms are combined on a single slide on which engraved markings indicate aperture in use (numbered 1 - 3) and give a scale of slit heights, divided 0 - [18] (mm) numbered by 5 subdivided to 1. A lever operates a shuttern at the back.

9. Cardboard box with handwritten marking ‘Parts for Spectrum projector’. Contains white metal tube with mount for bulb at one end and cloth covered electrical flex at other, with grey-green painted metal cross-piece; 12v light bulb; Dallmeyer super-six anastigmat 1 inch focal length f.1.9 aperture lens (serial number 492080) in grey-green painted brass mount; 2 washers; 2 knurled screws with washers; 2 screws. This part is quite possible not for the spectrograph or spectrum comparator, and may be for another instrument (perhaps 3269?)

Condition good; complete

References

Events