Sara, et al, Of all the Porter dials I've seen the CalTech dial (cylindrical equatorial - I suppose best describes it) comes closest to matching that modeled image provided by Aleks. However, as you note the stylus of the CalTech dial is not projecting radially from the plate surface, like that shown in the image.
Lastly, if I recall correctly, the CalTech dial had two seasonal plates (each having one of the two halves of the analemma engraved) and one of the them still remains at CalTech. Alas, they didn't get everything! Luke Coletti On 5/20/2010 2:04 PM, Schechner, Sara wrote: > I agree that it looks like a cylindrical equatorial dial, but it is only > vaguely similar to Porter's. Look at the difference in the gnomon and its > alignment. I'll try to dig up a better photo of Porter's dials. > > Cheers, > Sara > > -----Original Message----- > From: LJ Coletti [mailto:[email protected]] > Sent: Thursday, May 20, 2010 4:04 PM > To: Schechner, Sara > Cc: [email protected] > Subject: Re: Russell Porter Sundial? > > Sara, > > That looks similar to a cylindrical equatorial dial done by Porter while > at CalTech. The dial incorporated EoT correction and was, apparently, > stolen (URL below). > > http://pr.caltech.edu/periodicals/caltechnews/articles/v42/sundial.html > > Luke Coletti > > On 5/20/2010 12:34 PM, Schechner, Sara wrote: >> I have never seen this form associated with Russell Porter, but will check >> further. However, I think we need more information to tell the >> conventional type. For example, is the long rod the gnomon, and is it to >> scale with the arc? What do the hour lines look like? Does the sundial >> include both wooden objects set up as a pair, or just a single one? >> >> Sara >> >> Sara J. Schechner, Ph.D. >> David P. Wheatland Curator of the Collection of Historical Scientific >> Instruments >> Department of the History of Science, Harvard University >> Science Center 251c, 1 Oxford Street, Cambridge, MA 02138 >> Tel: 617-496-9542 | Fax: 617-496-5932 | [email protected] >> http://www.fas.harvard.edu/~hsdept/chsi.html >> >> >> >> -----Original Message----- >> From: [email protected] [mailto:[email protected]] On >> Behalf Of >> Sent: Thursday, May 20, 2010 2:45 PM >> To: [email protected] >> Subject: Russell Porter Sundial? >> >> Friends, >> >> Is there a conventional name (like horizontal', equatorial', polar' and >> so on) for the sundial constructed as shown below? >> >> Am I right thinking that the name of this construction is "Russell sundial"? >> I mean Prof. Russell Porter, the Palomar Mountain Observatory. >> >> Any help, please. >> >> Aleks >> www.sundials.ru >> >> >> --------------------------------------------------- >> https://lists.uni-koeln.de/mailman/listinfo/sundial >> > --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
