General Information

Serial #

N/A

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

METALS, INCLUDING BRONZE, GOLD & ALUMINUM, GLASS & SYNTHETIC CONSTRUCTION. METAL CASE LID PADDED WITH FOAM & FABRIC, AND FITTED WITH LEATHER HANDLES & METAL HARDWARE & HEAVY-DUTY HANDLES

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

89.0 cm

Width

72.0 cm

Height

77.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Physics

Category

Geophysics

Sub-Category

N/A

Manufacturer

AKA

Observatory CA

Country

Canada

State/Province

Ontario

City

Ottawa

Context

Country

Canada

State/Province

Ontario

Period

C.1960-1970S, THIS FORM

Canada

DESIGNED, BUILT & USED BY STAFF AT DOMINION OBSERVATORY, OTTAWA ON CANADA. SIGNIFICANT IN THE DEV'T OF THE VARIOUS FORMS OF THE CBPA WAS THE WORK OF L.G.D. THOMPSON (1954-57) AND H.D. VALLIANT (1960-65). GILDING OF CHAMBER DESIGNED TO REDUCE TEMPERATURE FLUCTUATIONS.

Function

TO MEASURE THE INTENSITY OF GRAVITY

Technical

SPRING-TYPE GRAVIMETERS IMPROVED RAPIDLY AFTER WWII, AND LARGELY REPLACED PENDULUMS FOR USE IN GEOPHYSICAL SURVEYS. PENDULUM APPARATUS REMAINED USEFUL FOR LONG RANGE GRAVITY TIES WHERE THE LARGE CHANGE IN GRAVITY COULD NOT BE RELIABLY ACCOMODATED BY SPRING-TYPE GRAVIMETERS. FOR THIS REASON FURTHER DEV'T OF PENDULUM APPARATUS CONT'D IN 1950S-1960S. BY MID-1970S PENDULUM MEASUREMENTS NO LONGER REQ'D (SEE 'THE CDN PENDULUM APPARATUS' PAPER-S.I/ 'K.E.' INDICATES KNIFE EDGE OF PENDULUM

Area Notes

Unknown

Details

Markings

DECAL APPLIED TO BASE OF PENDULUM APPARATUS READS: 'MRC/ V-4/ SERIES/ MRC MANUFACTURING CORPORATION/ ORANGEBURG, NEW YORK/ PAT. PENDING'. DECAL APPLIED TO SEVERAL PORTS READS: 'MRC MANUFACTURING COPRORATION'. DYMO LABELS APPLIED TO PORTS, CONNECTORS, ETC. IDENTIFY 'SHIELD/ THERMISTORS', 'K.E. 1' & 'K.E. 2'. LABEL ON CASE READS: 'Pend./ 2/ 3/ 5/ 6/ KE-2/ 480/ 440/ 195/ 190'. OTHER MKGS PRESENT BUT INACCESSIBLE FOR RECORDING/ PLATE SCREWED TO CASE FRONT READS: 'PYLON/ MADE BY/ PYLON ELECTRONIC DEVELOPMENT/ company, ltd./ MONTREAL. CANADA'; STAMPED BELOW: 'CASE NO.1124'/ 'TO/ Government of Canada/ EMR/ EARTH PHYSICS BRANCH 3 OBSERVATORY/ CRESCENT/ OTTAWA/ ONT' ON CASE LID

Missing

UNKNOWN. NO AUXILIARY EQ. RECV'D WITH DEVICE, IE. VACUUM PUMP, TEMPERATURE & SWING MEASURING EQUIPMENT (ELECTRONIC VERSIONS)/ 6 MENDENHALL TYPE PENDULUMS 930234.1-.6 & TEST PENDULUMS 872133.3 & 872133.4 USED ON CBPA From CA of 02/04/2002 by Matthew Bruce: No - appears complete

Finish

VACUUM CHAMBER DOME, WHICH IS GLASS, HAS BEEN GOLD PLATED, AS ARE THE SIX BRONZE PENDULUMS WHICH SWUNG WITHIN. BASE AND PROTECTIVE FRAME HAVE BRUSHED SILVER FINISH. SHEET METAL CASE PAINTED SILVER GREY; MEDIUM-BLUE COTTON LINERINSIDE LID.

Decoration

N/A