Dotting Instrument
date: label: date made
content: early 20th century
notes: label: Description
content: This 2-1/4" German silver drawing instrument consists of a teardrop-shaped plate to which is attached a mechanism that links a serrated wheel to a bar that holds a pen point. When the wheel is rolled along the edge of a T-square or straight edge, the pen point bounces up and down to make a line of dots. Draftsmen would then retrace and fill in the line, if desired, while they were finishing an engineering drawing.
label: Description
content: Underneath the uniformly serrated German silver wheel is a brass wheel with a pattern of three and one serrations. This wheel is marked: 6. It could be interchanged with one of four other brass wheels to change the dotting pattern. The instrument originally had six pattern wheels, but the one numbered with a "2" is missing.
label: Description
content: The back of the plate is marked: 1050. The instrument is in a rectangular wooden case covered with brown and black leather and lined with dark blue velvet and satin. The Eugene Dietzgen Co. of Chicago and Technical Supply Company (TSC) of Scranton, Pa., sold a similar dotting instrument in the early 20th century for prices ranging from $4.20 to $5.15. According to the 1904 Dietzgen catalog, E. O. Richter of Germany made the instrument sold at that time. Unlike the Dietzgen and TSC instruments, this example has a screw that allows the pen point to be removed from the bar. Compare to 1982.0147.01.
label: Description
content: References: <i>Catalog of Eugene Dietzgen Co.</i>, 7th ed. (Chicago, 1904), 88; <i>Catalog of Eugene Dietzgen Co.</i>, 12th ed. (Chicago, 1926), 84; Technical Supply Company, <i>Complete Catalog and Supply List</i>, 5th ed. (Scranton, Pa., 1912), 91.
label: Location
content: Currently not on view
topic: label: Subject
content: Mathematics
label: Subject
content: Drafting, Engineering
label: Subject
content: Drawing Instruments
setName: label: See more items in
content: Medicine and Science: Mathematics
label: See more items in
content: Pens and Pencils
label: See more items in
content: Science & Mathematics
creditLine: label: Credit Line
content: Gift of Howard I. Chappelle
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1987.0788.02
label: accession number
content: 1987.0788
label: catalog number
content: 1987.0788.02
objectType: label: Object Name
content: pen, dotting
physicalDescription: label: Physical Description
content: german silver (overall material)
label: Physical Description
content: brass (overall material)
label: Physical Description
content: wood (overall material)
label: Physical Description
content: leather (overall material)
label: Physical Description
content: cloth (overall material)
label: Measurements
content: overall: 1.7 cm x 9.7 cm x 6.8 cm; 21/32 in x 3 13/16 in x 2 11/16 in