• There are references to similar sectors to the ones in this collection in the collections of the the Metropolitan Museum of Art, the British Museum, and the National Museum of Scotland.
• “Modern instruments and methods of calculation; a handbook of the Napier tercentenary exhibition”, Cornell University and Commission on Pres- ervation and Access and the Xerox Corporation. Digital file copy- right by Cornell University Library 1991. Historical Math Monographs. http://home.tiscali.nl/~ajmdeman/ [accessed 28 Nov 2011] refers to: “21. Silver, compass (small size), four dials. Butterfield a Paris. French, late seventeenth century. 26. Silver, compass, octagonal, four scales. Butterfield a Paris.”

Michael Butterfield, was an English clockmaker who moved to France and worked in Paris. He was born in 1635 and worked in Paris between ~1680–1724. According to one source he moved to Paris in about the year 1685 where he became engineer to the King.

References

Modern instruments and methods of calculation; a handbook of the Napier tercentenary exhibition, Cornell University and Commission on Pres- ervation and Access and the Xerox Corporation. Digital file copy- right by Cornell University Library 1991. Historical Math Monographs. http://home.tiscali.nl/~ajmdeman/ [accessed 28 Nov 2011]