General Information

Serial #

N/A

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

BRASS

Dimensions

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

Length

32.3 cm

Width

7.8 cm

Height

N/A

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Marine Transportation

Category

Navigation instruments & equipment

Sub-Category

N/A

Manufacturer

AKA

Adams

Country

England

State/Province

Unknown

City

London

Context

Country

Canada

State/Province

Ontario

Period

MID-19TH C.+

Canada

ORIGINALLY OWNED BY JOSEPH CROMWELL, OLS. JOHN MCLATCHIE WAS HIS APPRENTICE IN 1864- SEE MCLATCHIE COLLECTION 780715-780753

Function

CALCULATING INSTRUMENT USED TO SOLVE VARIETY OF MATHEMATICAL PROBLEMS BY SURVEYORS, MARINERS, ENGINEERS & SCIENTISTS

Technical

SECTORS WERE USED FOR DRAWING, MEASUREMENT & CALCULATING PURPOSES AND MAY BE CONSIDERED THE FORERUNNER OF THE SLIDE RULE. BASED ON THE PROPERTIES OF SIMILAR TRIANGLES, AND USED WITH A PAIR OF DIVIDERS, THE SECTOR WAS USED TO SOLVE A VARIETY OF PROBLEMS QUICKLY & WITHOUT CALCULATION. ROUTINELY USED BY SURVEYORS IN MID 19THC.

Area Notes

Unknown

Details

Markings

'Made by GEO' ADAMS in/ Fleet Street, LONDON' INCISED IN SCRIPT ON SECTOR FACE, NEAR JOINT. MANY SCALES INCISED ON BOTH SIDES OF 2 RULES; 3RD FOLDING ARM IS UNMARKED. SCALES ON FACE OF TOP ARM LABELLED AS FOLLOWS: [2 UNMARKED]/ 'SIN'/ 'Sec'/ 'Cho'/ 'Poly'; LOWER ARM: 'Poly'/ 'Sin'/ 'Sec'/ 'Cho'/ 'Ten'/ 'V.Sin'/ 'Sin'/ 'Num'. REVERSE SIDE SCALES LABELLED AS FOLLOWS: 'J'/ 'F'/ 'Tan'/ 'tan'/ 'Lin'; LOWER ARM: 'Tan'/ 'tan'/ 'Lin'. SHORTER SCALES IN MIDSECTION ON TOP RULE LABELLED 'Hours'/ 'Chords'; CORRESPONDING HALF OF RESPECTIVE SCALES ON LOWER ARM LABELLED 'Latitu' & 'In.Mer.'

Missing

NONE

Finish

TRACES OF LACQUER ON BRASS REMAIN ON SECTOR: CONCEALED 3RD RULE HAS WELL PRESERVED LACQUERED BRASS FINISH

Decoration

FEATHER-LIKE FLOURISH ENGRAVED AFTER MFR'S MARKINGS