At the 2006 NASS Conference in Vancouver, British Columbia, Canada, Fred Sawyer announced that the Sawyer Dialing Prize for 2006 is given to Hendrik Hollander, “for his innovative design of a mean-time planar sundial with oblique conical gnomon and modified hour lines and day curves – resulting in a sundial adapted to modern timekeeping while retaining the aesthetic appeal of the familiar dial face.” Fer J. de Vries was able to present the dial to Hendrik in The Netherlands.

One of Hendrik’s conical gnomon dials is on the cover of the September 2006 [Vol. 13, No. 3] issue of The Compendium.  Inside that issue Hendrik explains in detail how the cone dial and a number of other bi-gnomon sundials work.   In response to the Sawyer Dialing Prize Hendrik sent a letter of thanks to the NASS conference.

http://www.artisanindustrials.com/world-of-sundials/spectra-sundial-amsterdam-netherlands.html