Dear all, It is possible (and easy) to get ecliptic obliquity computing half of tropic distance that is the difference of sun merdian elevation in soltsices, just using a trivial gnomon.
In the famous florentine church S. Maria Novella, there are some astronomical instruments. Among them an elevation quadrant and this claim by Egnatio Danti: ... Diligenti observatione perspecta, tropicorum distantioa grad. 46 mi. 56 sec 39..... But the measurement was not really good... Best regards Piero Ranfagni ************************************************************************ * Piero Ranfagni * * office Tel +39 055 2752 308 * * fax +39 055 2752 292 * * e-mail [EMAIL PROTECTED] * * www www.arcetri.astro.it/Italiano/EduPage * * * * Home Tel +39 055 487209 * * Tel +39 0588 23037 * ************************************************************************ -
