Page 108 - Kennemerland VOC ship, 1664 - Published Reports
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R.PRICE AND K. MUCKELEOY:THEKENNEMERLAND
Figure 28. A pocket sundial, opened into its three elements.
chord, rather than the arc, of a circle around the horizon vane. This form is particularly associated with early Dutch practice, as de- scribed in w. J, Blaeu’s Eerste deel der See- spiegel (1623), published in English as The Sea Mirrour (1625); a copy of his illustration of such an instrument is given in Fig. 27. A similar instrument is illustrated in Way- mouth’s TheJeweZZ ofArtes (1604), aithough the transom in this example is somewhat different in that it represents a tangent to the circle, rather than a chord. Assuming that this example was assembled in the most
obvious way, then it is graduated for reading zenith distance rather than altitude, which accords with Cmdr. Water’s conclusion that this became standard practice with such instruments during the early 17th century (Waters, 1958: 305-6). From the fact that
Figure 29. The dials of the two pocket sundials, both with their gnomons folded. Actual size.
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