General Information

Serial #

36867

Part Number

1

Total Parts

10

AKA

N/A

Patents

N/A

General Description

PRIMARILY METAL CONSTRUCTION. GLASS OPTICS & THERMOMETER ON .1. SOME SYNTHETIC COMPONENT PIECES. .2 FITTED WITH GLASS SUNSHADE OVER CIRCLE & 2 GLASS LEVEL VIALS; HORIZONTAL CIRCLE DIVIDED ON SILVER. CASES FOR .1-.2, .8-.10 MADE OF WOOD

Dimensions

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

Length

111.0 cm

Width

41.0 cm

Height

27.7 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Physics

Category

Geophysics

Sub-Category

N/A

Manufacturer

AKA

Suss

Country

Hungary

State/Province

Unknown

City

Budapest

Context

Country

Canada

State/Province

Ontario

Period

THIS INSTRUMENT USED BETWEEN 1928-1935. THIS TYPE OF INSTRUMENT USED LATE 1920S- EARLY 1930S (REF.1, P.167)

Canada

ONE OF TWO EOTVOS-TYPE TORSION BALANCES PURCHASED FOR JOINT USE OF DOMINION OBSERVATORY & GEOLOGICAL SURVEY. THESE INSTRUMENTS WERE AMONG THE FIRST IN CANADA. A.H. MILLER (1886-1962), USED THESE BALANCES, AND OTHER EQ. IN SOME OF THE EARLIEST GRAVITY SURVEYS & ISOSTACY STUDIES CONDUCTED IN CANADA (REF.2) SEE ALSO 872131

Function

TO MEASURE THE GRADIENT OF GRAVITY AT A SPECIFIC POINT OR LOCATION, AND THE CURVATURE OF THE EQUIPOTENTIAL SURFACE.

Technical

DEV'T BY HUNGARIAN BARON ROLAND VON EOTVOS THE TORSION BALANCE BECAME ONE OF THE MAIN INSTS. USED IN GEOPHYSICAL PROSPECTING IN L.1920S-E.1930S. THE BALANCE CONSISTS OF A HORIZONTAL BEAM WITH A MASS AT EITHER END (ONE ON THE BEAM, ONE SUSPENDED FROM IT), THE WHOLE SYSTEM SUSPENDED BY A TORSION FIBRE. THE BEAM WAS SET IN A PARTICULAR AZIMUTH, RELEASED, AND THE TENSION IN THE SUSPENDING FIBRE NECESSARY TO PRODUCE EQUILIBRIUM NOTED. THE BEAM WAS THEN RESET AND MEASUREMENTS REPEATED, THROUGH A SEQUENCE OF 5 AZIMUTHS. IT TOOK APPROX. 1 HOUR FOR THE BEAM TO COME TO REST. BALANCES HAVING 2 BEAMS, LIKE 872121, CUT TIME IN HALF, REQUIRING ONLY 3 SETS OF OBSERVATIONS. (Ref.1, p.167)

Area Notes

Unknown

Details

Markings

TWO LOGOS- 1 A HERALDIC SHIELD, 1 A TRANSIT MARKED 'S', AND TEXT 'Original Eotvos/ Made in Hungary/ Suss Nandor R.T./ Budapest/ 36867' INCISED ON CENTER FRONT OF BALANCE. BALANCE ARMS LABELLED 'I' & 'II'; LOCKING COLLARS ON EACH BEAM LABELLED 'FREE <-I-> FAST' & 'FREE<- II-> FAST'. TWO B&W PHOTOS OF BUDAPEST GLUED INSIDE CASE; GLUED INSIDE LID IS NOTICE: 'Caution/ Do not forget to take out the fixing plates from the/ innermost boxes before making the balances free/ The plates are only to be used exceptionally for long/ transports and not at all during the Survey/ First free below and then above'/ .1PT case: ‘On the contrary fasten first above and then below!/ The cap is screwed on the top of the instrument. Attention to the thermometer when taking out or/ putting in the instrument!/ BARO EOTVOS LORANS/ BUDAPEST/ GEOFIZIKAIINTEZET ". SN " 36867 " incised on case lid, above latch. "45 lbs/ #263/ 36867/ SATELLITE/ ANTENNA " handwritten in black marker on case top. Shipping tag tied to case includes text : " SHIP/ TO/ Dr. J.R. Weber/ Dominion Observatory/ Ottawa, Ont./ ... PACKAGE/ NUMBER 46/ FROM PCSP, A617, NWT "./ .1PT case: ‘On the contrary fasten first above and then below!/ The cap is screwed on the top of the instrument. Attention to the thermometer when taking out or/ putting in the instrument!/ BARO EOTVOS LORANS/ BUDAPEST/ GEOFIZIKAIINTEZET ". SN " 36867 " incised on case lid, above latch. "45 lbs/ #263/ 36867/ SATELLITE/ ANTENNA " handwritten in black marker on case top. Shipping tag tied to case includes text : " SHIP/ TO/ Dr. J.R. Weber/ Dominion Observatory/ Ottawa, Ont./ ... PACKAGE/ NUMBER 46/ FROM PCSP, A617, NWT ".

Missing

APPEARS COMPLETE. MUST BE USED WITHIN PORTABLE HUT IN ORDER TO SHIELD INST. FROM WIND, TEMP. ETC. From CA of 02/07/2002 by David Daley: Yes - empty compartment in small trunk suggests missing components

Finish

DULL, FLAT GREEN-GREY ENAMEL FINISH ON MOST COMPONENTS; SOME FITTINGS OR COMPONENT PARTS HAVE BLACK, WHITE METAL AND/OR LACQUERED BRASS FINISHES. .1PT & .2 PT CASES HAVE GREY PAINTED EXTERIOR, LACQUERED FINISH ON INTERIOR, WITH SOME GREEN FELT PADDING.

Decoration

N/A