----- Original Message ----- From: "Frank Evans" <[EMAIL PROTECTED]> To: "Sundial" <[email protected]> Sent: Wednesday, October 12, 2005 3:16 AM Subject: equation of time
> Greetings fellow dialists > > In his recent article on the equation of time in BSS Bulletin 17 (iii), > Chris Daniel writes that the earliest appearance of the analemma in a UK > publication is perhaps the illustration in the second edition of Mrs. > Gatty's sundial book, dated 1889. Here the figure and construction > details are the work of Wigham Richardson, a Tyneside shipbuilder. In > his diagram the familiar "figure of eight" is superimposed on the noon > line. Of necessity such a construction demands a nodus on the gnomon and > we may describe the arrangement as a graphic indicator of the equation > of time through the year. > > Earlier, in 1881 Wigham Richardson made a sundial which he placed at the > entrance to his shipyard. This dial bore a curve stretched over a > straight line, which was also clearly an expression of the equation of > time. Unfortunately neither the old photograph of the dial in situ nor > the more recently repainted dial shows any indication of the months to > which the parts of the curve are related. But they must originally have > been present. > > Such a snake-like curve is not an indicator of the equation of time but > a graphic illustration of its changes through the year. > > My question is: Was this, like Richardson's appendix in Mrs. Gatty's > book, a first appearance of an equation of time line? Can anyone supply > earlier earlier examples of such a line on dials either in the UK or > elsewhere? > > Frank 55N 1W > Lloyd Mifflin (sp?) obtained a US patent for a sundial with an analemma in or around 1867 Dave G. http://atensundials.com -
