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Details

Numéro d'artefact
2002.0291.005
contexte Fonction
USED TO MEASURE LATITUDE, AND FOR TIME DETERMINATION.
contexte technique
PZT IS VERTICALLY MOUNTED TELESCOPE USING POOL OF MERCURY AT BOTTOM TO ENSURE THE LINE OF SIGHT IS EXACTLY TO/AT THE ZENITH. CONCEIVED BY SIR GEORGE AIRY IN 1854, THE 1ST PZT WAS BUILT C.1909 BY FRANK ROSS. IN 1911 IT WAS PLACED IN OPERATION IN MARYLAND FOR USE BY THE US COAST & GEODETIC SURVEY. BY 1960, 9 OTHERS WERE BUILT & INSTALLED IN OBSERVATORIES AROUND THE WORLD. (REF. 1)
contexte Canada
2ND, LATER PHOTOGRAPHIC ZENITH TELESCOPE (PZT) BUILT AT US NAVAL OBSERVATORY C. 1967-8, AND USED AT DOMINION OBS. IN OTTAWA UNTIL EARLY 1990S. IT REPLACED ORIGINAL PZT BUILT IN 1951 BY DOMINION OBSERVATORY SHOPS (PRECISION COMPONENTS); VICKERS LTD., MONTREAL (CASTINGS); AND PERKIN ELMER CO., GLENBROOK, CT (OBJECTIVE). ( REF.1)
Description
METAL, GLASS, AND SYNTHETIC MATERIALS OF CONSTRUCTION
Nombres de pièces
42
Fini(s) de l'artefact
Silver-green enamel painted front panel fitted with black tuning dials and silver metal lifting handles. Top, side and back panels are silver-green metal. Black synthetic covered electrical cord. Amber-colour synthetic (?) tube secured to casing top.
Marques sur l'artefact
"RACAL" printed on red metal plate on front panel. All controls, etc. labelled. Black & white inventory detail on upper right of front panel reads "GR 64344/ DO NOT REMOVE THIS TAG". Mfr's plate fixed to back panel reads "BRITISH PAT. NO. 714684 13.3.51./ U.S. PAT. APPLIED FOR/ AUSTRALIAN PAT. NO. 158530 21.3.50./ RECEIVER/ TYPE NO./ RA. 17C12/ SERIAL NO./ 9626/ RACAL ELECTRONICS LTD./ BRACKNELL BERKSHIRE/ MADE IN ENGLAND". All controls, etc. on back panel are labelled.
Groupe 1
Astronomie
Catégorie 1
Équipement d'observation
Sous-catégorie 1
Télescopes optiques
Matériau(x)
métal;verre;synthétique