General Information

Serial #

N/A

Part Number

10

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

48.3 cm

Width

8.0 cm

Height

2.5 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

Torsion wire box NB: Box designed to contain 2 wires: these are secured behind the paper label, and are almost invisible. USE EXTREME CAUTION IN HANDLING EITHER THE LABEL OR THE WIRES./ Presumed to be alternate or spare wires: case is not stamped with balance serial number, and there is no provision for storage of this box within larger cases. Paper label fastened over wires bears following handwritten text: " Length= 40.cm/ { Torsion-wire No. XV.b 48. Torsion constant: 0.04030 CGS. Temperature coefficient: +0.054. sc. div./ Torsion-wire No. XV.b.54 Torsion constant: 0.04065 CGS. Temperature coefficient: +0.061 sc.div. ". Blue ink stamp on label reads: " BARO EOTVOS LORANO/ BUDAPEST/ GEOFIZIKAIINTEZET ". 4 screw fastening label over torsion wires- each incised "MURILLO/ No. 3 ".

Missing

From CA of 02/07/2002 by David Daley: Yes - empty compartment in small trunk suggests missing components

Finish

Unknown

Decoration

N/A