La Filotecnica Rolling Parallel Rule

Description:

This ten-inch German silver instrument has two rollers connected by a shaft. Both ends have knobs to hold while rolling the parallel rule. Both long edges have centimeter scales, divided to millimeters and numbered by ones from 0 to 24. The instrument is marked: "LA FILOTECNICA" MILANO. A wooden case is lined with dark blue velvet and has ornate brass clasps. The bottom of the case is marked in red pencil: S_301 £ £ £.

Ignasio Porro (1801–1875) established La Filotecnica in Milan in 1865 to train students to make optical and mathematical instruments. Between 1870 and 1877, one of his apprentices, Angelo Salmoiraghi (1848–1939), purchased the firm and put more emphasis on manufacturing. By 1906 the company was renamed Filotecnica Salmoiraghi.

References: Paolo Brenni, "Italian Scientific Instrument Makers of the Nineteenth Century and Their Instruments," in Nineteenth-Century Instruments and Their Makers, ed. P. R. de Clercq (Amsterdam: Rodopi B.V., 1985), 196–198; Bill Morris, "A Fine Sextant by Filotecnica Salmoiraghi of Milan," October 5, 2010, The Nautical Sextant, http://sextantbook.com/2010/10/05/a-fine-sextant-by-filotecnica-salmoirhagi-of-milan/.

Date Made: ca 1870

Maker: Officina Filotecnica

Location: Currently not on view

Place Made: Italy: Lombardy, Milan

Subject: MathematicsDrafting, Engineering

Subject:

See more items in: Medicine and Science: Mathematics, Science & Mathematics, Parallel Rules

Exhibition:

Exhibition Location:

Credit Line: Gift of Ursula N. Forbes

Data Source: National Museum of American History

Id Number: 1986.0316.04Catalog Number: 1986.0316.04Accession Number: 1986.0316

Object Name: parallel rule in caseparallel rule

Physical Description: german silver (overall material)wood (overall material)fabric (overall material)Measurements: overall: 3.8 cm x 27.5 cm x 7.5 cm; 1 1/2 in x 10 13/16 in x 2 15/16 in

Guid: http://n2t.net/ark:/65665/ng49ca746a5-0787-704b-e053-15f76fa0b4fa

Record Id: nmah_690223

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