Beyond the introduction of the spider line it is unnecessary to mention the various steps by which the Gascoigne micrometer assumed the modern forms now in use, or to describe in detail the suggestions of Hooke, 4 Wren, Smeaton, Cassini, Bradley, Maskelyne, Herschel, Arago, Pearson, Bessel, Struve, Dawes, &c., or the successive productions of the great artists Ramsden, Troughton, Fraunhofer, Ertel, Simms, Cooke, Grubb, Clarke and Repsold.
Simms in defence of the politics and finance of the South, enjoyed a shorter career.
It consists in the introduction by Simms of a fifth lens, but no satisfactory description has ever appeared.
Simms, was privately printed by the Bradford Club, New York, in 1867.
Simms, Geography of South Carolina (Charleston, 1843).
