5. MARTHA KALTOFF, wife of Caspar Kaltoff, who is named in letters patent dated 1672, _as lately deceased_. Her family was--
CATHARINE, married to Claude Denis. CASPAR KALTOFF, and his unmarried sister-- ISABEL KALTOFF.
6. PETER JACOBSON, a sugar refiner, who married one of Kaltoff's daughters, had a portion of the buildings at Vauxhall, where the Water-commanding Engine was erected, and in operation from 1663, till at least to the year 1669, if not some years later.
7. WILLIAM LAMBERT, another workman, a founder at Vauxhall, in the reign of Charles I., "under the Marquis of Worcester, for gun and waterwork, or any other thing founded in brass," in 1647, and who was living in 1664-5.
8. CHRISTOPHER COPLEY, who had been a Colonel in the Parliamentary service, and was probably an iron master, having been the proprietor of four Iron Works. He assisted the Marquis at an early period and held a pecuniary interest in his invention of a Water-commanding Engine. Indeed it is highly probable that he was the "powerful friend" at whose instigation the "Century" was written in 1665.
9. The EARL OF LOTHERDALE, written to in January, 1660, had a copy of the "Definition" of the Engine sent to him, and is promised an ingeniously contrived box or cabinet. He was appointed as late as March, 1665, to be one of a Commission to report on the affairs of the Marquis, and must, therefore, have been familiar with all matters relating to the noble inventor.
10. DR. ROBERT HOOK, the eminent mathematician, was acquainted with Caspar Kaltoff, and early in 1667, went purposely to see the engine working at Vauxhall, having read the "Definition."
11. THE HONOURABLE ROBERT BOYLE received from Dr. Hook a copy of the "Definition," sent to him with a letter on the subject.
12. LORD BRERETON is specially mentioned by Dr. Hook, as being so confirmed in his doubts of the excellence of the Marquis's engine, that he had laid a wager on the subject.
13. HENRY SOMERSET, Lord Herbert, afterwards created first Duke of Beaufort, by Charles II., must have frequently seen the engine in operation. He died in 1699.
14. JAMES ROLLOCK, who wrote a poetic eulogy on the Engine about 1663, speaks of himself as "an ancient servant," having known his lordship forty years, dating back to 1623.[7]