| Signature | Maker | Instruments | Comments | Location | References | 
| GREATOREX, RALPH | England, 1625-1712, MIM PHIM | Ring Sundial = Wisbech; Weather Glass, 1663 = Samuel Pepys; Air Pump, 1658 = Robert Boyle; Universal Ring Sundial = OXF. | apprenticed to Thomas Dawson of the Clockmakers' Company; turned over to Elias Allen of the Clockmakers' Company on March 9, 1639, free of the Company on Nov. 25, 1653; probably the "R.G." 1 on compass cards; T.C. | at the sign of Adam and Eve, south side of the Strand; Temple Bar; both in London. | Taylor 1(218); Holbrook; DNB; Clay and Court; Bell 2; Crawforth 1; J. Brown 1; Latham and Matthews; Robischon; A.J. Turner 10. | 
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