General Information

Serial #

N/A

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

BRASS COMPASS CASING & COVER, SIGHT VANES & VERTICAL ARC, LEVEL CASINGS, TRIPOD MOUNTING, AND MOST FITTINGS. GLASS COMPASS FACE COVER & LEVEL VIALS. SILVER COMPASS FACE & CIRCLE. FLUID FILLED TUBE LEVELS. JEWELLED CENTRE IN NEEDLE PIVOT CAP. VERTICAL ARC & VERNIER DIVIDED ON SILVER; THIN BRASS WASH FINISH.

Dimensions

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

Length

22.0 cm

Width

16.0 cm

Height

15.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Exploration and Survey

Category

Measurement-angles

Sub-Category

N/A

Manufacturer

AKA

WILTON

Country

England

State/Province

Cornwall

City

St. Day

Context

Country

Canada

State/Province

Ontario

Period

19TH CENTURY

Canada

CIRCUMFERENTORS WERE VERY POPULAR IN N.A. WHERE, WITH THE MAGNETIC NEEDLE ACTING AS REFERENCE, IT WAS IDEAL FOR SURVEYING FORESTED OR OPEN AREAS, WITH FEW ARTIFICIAL LANDMARKS.

Function

TO DETERMINE DIRECTION, AND MEASURE HORIZONTAL ANGLES

Technical

A STANDARD CIRCUMFERENTOR IS ALSO KNOWN AS A MINER'S DIAL. IN MINE SURVEYING THE SURVEYOR IS REQUIRED TO FIX DIRECTION WITHOUT REFERENCE TO LANDMARKS, AND MUST RELY HEAVILY ON THE MAGNETIC COMPASS. FOR THIS REASON MINER'S DIALS, AS DO ALL MINING INSTRUMENTS (BEFORE COMPUTERIZATION) FEATURE A LARGE, PROMINENT COMPASS.

Area Notes

Unknown

Details

Markings

'Willm Wilton/ ST. DAY/ CORNWALL' INCISED ON COMPASS FACE. QUADRANTS & HALF-QUADRANTS LABELLED. COMPASS FACE DIVIDED 0-90-0-90, AT 10-DEGREE INTERVALS. COMPASS CIRCLE, ABOVE, DIVIDED 360-0, BY SINGLE DEGREES/ 'W WiltonSt. Day' INCISED ON FACE OF VERTICAL ARC. ARC DIVIDED +90-0-90+, AT 30-MINUTE INTERVALS; VERNIER DIVIDED 15-0-15, AT 5-MINUTE INTERVALS. ON REVERSE SIDE OF ARC: INSIDE SCALE LABELLED 'Perpen'r' & DIVIDED 6-0 & 0-6 (FEET) AT 1-INCH INTERVALS; OUTSIDE SCALE LABELLED 'Underlie' & DIVIDED 0-6 & 6-0 (FEET) AT 1-INCH INTERVALS.

Missing

SIGHT ON VERTICAL ARC DAMAGED & MISSING/ TUBE LEVEL ON VERTICAL ARC HAS PALE PINK LINER - LEVELS INSIDE COMPASS ARE SILVER- ONE OR OTHERS MAY NOT BE ORIGINALS

Finish

LACQUERED BRASS COMPASS, COVER & VERTICAL ARC. WASHED SILVER COMPASS FACE. CLEAR POLISHED JEWEL IN PIVOT CAP. BRASS WASH FINISH THINLY APPLIED TO SILVER ARC & VERNIER.

Decoration

NONE