DMM 38939

Museum: Deutsches Museum, Munich

Title: Sector by Michael Butterfield

Inventory number: DMM 38939

Signature: "Buterfield a paris."

Date: Between 1635 - 1724

Material: Brass

Dimensions: Lenght of limb: 110 mm; width: 13 mm

Description: See Schneider, 1970, p. 88.

Preliminary examination of the metallic scales: The front presents a metallic line with 6 values. Planetary symbols on the metal scale, indicated a "Les Metaux". Two other scales, each on a face, when the sector is opened at 180 degrees, on the border. Called respectively "poi des boulets" [sic] and "Calibre des pies" [sic].

References: Schneider, Ivo: Der Proportionalzirkel: Ein universelles Analogrecheninstrument der Vergangenheit. Deutsches Museum: Abhandlungen und Berichte. 38. Jahrgang 1970, Heft 2. München, Düsseldorf 1970, p. 88.

Maurice, Daumas: Les instruments scientifiques aux XVII^e et XVIII^e siecle. Paris, 1953, p. 107f.

Measurements of Scales (in mm)

"Les Metaux"

☉ [Sun, Gold]		79
♄ [Saturn, Lead]		93
☽ [Moon, Silver]		97
♀ [Venus, Copper]		101,5
♀ [repeats the Venus symbol, but it is iron]		105
♃ [Jupiter, Tin]		108

"Calibre des pies"

1/4	34
1/2	41
3/4	47
1	51
2	65
4	81,5
6	93
8	103
10	110
15	116
20	128
25	138
30	147
35	153
40	164
45	175
50	185,5
55	194
60	205

"poi des boulets"

Note: the first two points for 1/4 and 1/2 are poorly indicated. I assume that the line of the scale corresponds to the line of the fraction.

1/4	34
2 [1/2]	40
3/4	45
1	51
2	65
4	82
6	94,5
8	104
10	112
15	119
20	131,5
25	142
30	151
35	157
40	168
45	179
50	191
55	199
60	210