Equation of time
Dear all, I would like to know how the equation of time (EoT) is defined according to country. For example in France, traditionally: EoT = real time - mean time while in USA: Eot = mean time - real time. Could you tell me how you define the Eot in your country ? Many thanks Yvon Yvon MASSE 7, rue des Tilleuls 95300 PONTOISE FRANCE Mél: [EMAIL PROTECTED]
Equation of time
Hello all, Ooops!... Of course, I make a mistake: For example in France, traditionally: EoT = real time - mean time while in USA: Eot = mean time - real time. Please read: For example in France, traditionally: EoT = local mean time - solar time while in USA: Eot = solar time - local mean time. Yvon
Re: Error Orontii
Dear all, the Error Orontii is common in the gnomonic history. Pardies in his book Deux machines propres a faires les quadrans (1673) do it. I have also find it in the Encyclopédie méthodique of Panckoucke (1783-1832) at the article Amusements de gnomonique for the description of the Capuchin Dial. Yvon Yvon MASSE 7, rue des Tilleuls 95300 PONTOISE FRANCE E-mail: [EMAIL PROTECTED]
Some new things
Dear all, there are some new things on my website (but sorry in french): - How to draw an horizontal sundial with chiefly a compas - An old method for setting the style with only two points of shadow The URL have changed and is now: http://www.apro.fr/usr/ymasse/ Also my e-mail become: [EMAIL PROTECTED] Best regards Yvon Yvon MASSE 7, rue des Tilleuls 95300 PONTOISE FRANCE E-mail: [EMAIL PROTECTED]
Re: Capuchin hour limits
Hello all, the capuchin hour limit is a part of an equilatere hyperbola. Its center is K on Figure 3 of the Fer de Vries's article. By using a xy system of axis with origine at K, the equations of the assymptotes are, at the latitude L: y = - x.tan L/2 y = x.tan (90 - L/2) and the equation of the hyperbola: x.x - y.y + 2.x.y.cos L/sin L + BK.BK = 0 Of course, the point B is on the hyperbola and it's also the highest point. I came across this problem when I worked on the equations of the central projection analemmatic sundial with circular curve. Best regards Yvon Yvon MASSE 7, rue des Tilleuls 95300 PONTOISE FRANCE E-mail: [EMAIL PROTECTED]
