Re: Does Refraction Affect Azimuth? / Re: sundial Digest, Vol 24,

There is a Java applet showing the effects of refraction and flattening at: http://www.jgiesen.de/refract/index.html If it came from this list originally, I apologize in advance. --- https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Plastic Fake Stained Glass

Theater lighting gels are plastic sheets that come in a large variety of colors and are inexpensive. I don't know if they will stick to windows or would work in a computer printer. Rosco is one of the major brands. --- https://lists.uni-koeln.de/mai

Great circle calculation

There are a lot of navigation calculations at: http://williams.best.vwh.net/avform.htm It includes the distance and course between points. --- https://lists.uni-koeln.de/mailman/listinfo/sundial

Glynne replica dial

I have been given a sundial that may be a Glynne replica drawn by Fer deVries. I found it at a friends house in the suburbs of Boston, Massachusetts USA. The gnomon was mounted backwards. There are some pictures at: http://www.dickkoolish.com/rmk_page/pictures_060407.html The screws were steel

Re: Russell Porter sundial

An original Porter Garden Telescope recently sold at the Skinner auction in Boston. http://www.dickkoolish.com/rmk_page/pictures_032207.html There a couple of Porter sundials in the telescope making museum at the Hartness House in Springfield VT. http://www.dickkoolish.com/rmk_page/pictures_073

Re: Using "Google Patent" to find Sundial Patents.

Here is a sundial at Mt. Auburn Cemetery in Cambridge MA, USA. It's probably not a cremation container, but certainly could be. http://www.dickkoolish.com/rmk_page/sundials/payson_mtauburn.html > > Hi all, > > Was having a look at Google Patents using the key word "sundial" and = > found a nu

A list of sundials with GPS positions

I found a web page for www.waymarking.com, which is evidently a place for people to record the location of interesting things. There is a sundial catagory with 65 sundials listed. --- https://lists.uni-koeln.de/mailman/listinfo/sundial

Re: Moon Calendar DeltaCad macro

Two moon phase calculators that do exist are at: http://www.lunawheel.com/ http://www.moonstick.com/ > > Dear sundial friends, > To celebrate the solar eclipse tomorrow, I prepared a DeltaCad macro for > finding the MEAN MOON PHASES. > All callendar constructions use somehow corrections

Sky Pointer

I put some pictures of the Kennedal Sky Pointer on a web page at http://www.dickkoolish.com/rmk_page/pictures_032306.html. Sky Publishing used to sell them. You can set the RA and Dec of an object and the date and time and it will point to the position in the sky. Or you can set the Dec and rotat

Re: Moon rise/set on the equinox

> > > day, the declination of the moon changes a lot every day, > > since it goes through the cycle from maximum to minimum > > declination every month, while the sun takes a whole year > > to go through that cycle. > > Yes, I knew that. And I heard as well that the moon's > extreme declinations

Re: Moon rise/set on the equinox

On March 20, the declination of the sun is 0, so it rises due east and sets due west. The moons declination on that day is almost -26 degrees so it rises south of east. The full moon rise this past Tuesday was almost due east. Unlike the sun, whose declination changes just a bit every day, the de

safe solar filters

See: http://www.mreclipse.com/Totality/TotalityCh11.html This is from Fred Espenak at NASA. http://www.mreclipse.com/Totality/TotalityCh11.html -

Re: Star finder (astrolabe) for sale

> I'd like to draw your attention to a star finder for sale on the > Internet auction house eBay. See > > > I own one of these, though I have to confess I haven't looked after it > well and it is now missing some of the transpa

an item on eBay

Item 1498358081 Up for Auction. More Stuff from a Prominent Eastern Shore Collection. Here is a Wonderful Antique Helio-Chronometer or Sundial. We are by no means experts in this type of Time Piece or Astronomical Instrument & we will do our best to describe it and let our pix speak for themselve

pinhole photo of Portland sundial

There's a pinhole camera photo of the Portland Oregon Union Station sundial at: http://web.pdx.edu/%7Eharveyt/C1.html

Scientific Instruments Auction

Don Yeier, ex Vernonscope owner is having a scientific instruments auction on Saturday, May 19, 2001, in Candor, New York (near Binghamton). In addition to antique telescopes, binoculars, clocks, etc. the flyer says there is an Augsberg equitorial dial and other sundials. Catalog is $20.00 ($25.

Re: no mail ? Is it normal ?

> Actually it is dark, but the lights are on. See the amazing photo at > > http://antwrp.gsfc.nasa.gov/apod/image/0011/earthlights_dmsp_big.jpg > > Daniel Wenger We amateur astronomers call that 'Light Pollution'. http://www.darksky.org/ida/index.html

suns angular diameter

>From the web page: >http://sunearth.gsfc.nasa.gov/eclipse/SEhelp/SEgeometry.html "Eclipse geometry is complicated by the fact that Earth's orbit around the Sun is elliptical. As a result, the Sun's apparent semi-diameter varies from 944 arc-seconds at aphelion to 976 arc-seconds at perihelion.

does this work

Take a look at this sundial: http://www.angelsandearthlythings.com/hp4500.html I think it has problems. Am I correct?

outdoor decor sundial question

http://www.shopoutdoordecor.com I was looking at the Outdoor Decor web page and saw the Marble Sun Sundial. It's the second one down on the Historical and Disc sundials page. Is this a working sundial?

bad sundial illustration

The cover of the June 2000 issue of Embedded Systems programming has a sundial with the gnomon pointing in the wrong direction. I've already emailed them about it. It's on my web page at: http://linux.bbn.com/~koolish with the full scan in: http://linux.bbn.com/~koolish/sundial_cover.

Re: The Swensen Dial WebCam is going again.

> Isn't Beltane the other side of Candlemas? > I am looking forward to an authoritative answer based on solar declination. > > Roger Bailey Beltane explanation (and other cross-quarter days): http://www.isleofavalon.co.uk/edu/g-bank/articles/beltane.html

Stereographic projection circle proof

http://www.geom.umn.edu/docs/doyle/mpls/handouts/node33.html has a proof that circles on the sphere project as circles on the stereographic projection.

Re: The analemma

> There is an article in the most recent edition of Sky and Telescope magazine > about "photographing the analemma". > > It describes how photos have been taken which show the movement of the sun. > They rely on time lapse (either 365 or 12 exposures over the course of a > year), with each exposu

lunar perigee vs phase

The synodic month (full moon to full moon) averages 29.53 days, while the anomalistic month (perigee to perigee) is 27.55 days, so the phases drift with respect to perigee. see: http://www.treasure-troves.com/astro/AnomalisticMonth.html

NASA eclipse info page

There's a great web site for eclipse info, both solar and lunar at: http://sunearth.gsfc.nasa.gov/eclipse/eclipse.html

book sources

Two good sources (in the US at least) for books on astronomy and celestial navigation are: Sky Publishing 49 Bay State Road Cambridge, MA 02138 617-864-7360www.skypub.com Willmann-Bell, Inc. P.O. Box 35025 Richmond, VA 23235 804-320-7016www.will

Longitude book

There is now a new 'illustrated' version of Longitude by Dava Sobel, published, I think, in cooperation with the Harvard University collection of historic scientific instruments.

books on atmospheric phonomena

There's a page of books on atmospheric phonomena at: http://www.treasure-troves.com/astro/AtmosphericPhenomena.html One book that I like is: Greenler, R., Rainbows, Halos, and Glories, Cambridge University Press, 1980.

solar filter sources

A page of solar filter sources is: http://umbra.gsfc.nasa.gov/eclipse/970309/text/filter-sources.html

more on the bead in the hole

A paper recently put on the web about pinhole photography has a section about something called a 'Pinspeck Camera' that might have the same properties as the bead in the hole shadow sharpener. See: http://www.pinhole.com/resources/articles/Young/index.html and look down near the end of the arti

picture of sun tracking device

I've put a picture of what I think is a sun tracking device on my web page at linux.bbn.com/~koolish. If anybody has seen one or knows how it was used, let me know. There are no markings on it.

Re: a peculiar sharpener

Patrick Powers wrote: > It is simply the pin hole camera effect again. Light passing through any > small aperture is focused . As the hole's size is changed the focusing > parameters are changed too. So with a fixed distance from hole to plate > there will be one size that works. A different s

Large quartz sphere

It isn't clear, but there's a picture of a 960 pound, 27" smokey quartz sphere on a web page at: http://www.innerjourneys.com/sqz32601.htm A smaller clear one is at: http://www.netins.net/showcase/rockcutter/qzsph.htm

glsaa sphere

A web search turned up glass spheres at: http://www.angelsandearthlythings.com/s-sphere.html

Sundicator picture

I scanned the Sundicator and put an image on my web page: http://linux.bbn.com/~koolish Click on the small image to get the big image (296K).

Re: Name of sunlight recording device.

> It looks like a glass sphere held in the center of a small equatorial > sundial. The image of the sun focuses to a point at some short > distance away from the surface of the glass sphere. Held in place > at this distance away from the glass and following the curve of > the sphere is a piece

MIT Henge

We are coming up to the day when sunset lines up with the Infinite Corridor at MIT (Massachusetts Institute of Technology) in Cambridge, MA, USA. I may try and observe it this year. http://w3.mit.edu/afs/athena.mit.edu/org/p/planning/www/mithenge

books on atmospheric phonomena

There are a number of books on atmospheric phonomena, the classic one being "Light and Color in the Open Air" by Minnaert. A good one is "Rainbows, Halos and Glories" by Greenler. Sky Publishing and Willmann-Bell have some of these.

World Magnetic Model

http://www.ngdc.noaa.gov/seg/potfld/DoDWMM.shtml

Stellafane

Luke Coletti mentioned Stellafane in a message. Stellafane is the observing site and clubhouse in Springfield, Vermont, USA of the Springfield Telescope Makers, perhaps the oldest amateur astronomy club in the US. Springfield was the birthplace of amateur telescope making. Russell Porter, who l

Explanatory Supplement

After being out of print for many years, the Explanatory Supplement was re-written and re-published in 1992. It is now the Explanatory Supplement to the Astronomical Almanac, edited by Kenneth Seidelmann and is published by University Science Books, 20 Edgehill Rd, Mill Valley, CA 94941.

sundial references in The Pinhole Journal

The April 1998 (Vol 14 #1) issue of "The Pinhole Journal" is titled "A Tour of Renaissance Pinhole Sites in Italy. In addition to places related to art and perspective, they also visited places with noon marks, meridian lines and reflected sundials. Information about the Pinhole Journal is avail

lunar libration animation

I know this is slightly off-topic, but I thought it might be interesting. This is an animation of the lunar phases that clearly shows the libration. http://www.geocities.com/CapeCanaveral/5409/lunation.gif

movie player for UNIX systems

Daniel Roth's movies can be played on UNIX systems with the XAnim program. It's available from: http://xanim.va.pubnix.com/home.html

1998 sun/polaris dec table

The following web page has a table for every day of 1998, giving the declination of the sun, the equation of time, and the declination of Polaris. http://www.cadastral.com/eph1998b.htm

anybody use raytracing

There are free raytracing packages available that allow you to describe a 3-dimensional object and render an image of it with light sources placed at will. Has anybody used these to simulate sundials? Seems like it should work.

graph of refraction error

There is a graph of the refraction error at: http://www.cadastral.com/papersl1.htm

HO-260, Azimuths of the Sun

I've got an extra copy of Hydrographic Office publication HO-260, "Azimuths of the Sun", 1964 reprint. Older editions were HO-71. For $5.00 I'll mail it anywhere in the US.

Chaucers treatise on the astrolabe

http://www.fordham.edu/halsall/source/chaucer-astro.html

cartoon in the New Yorker

There is a sundial cartoon in the March 9th issue of the New Yorker magazine. I scanned it in and put it on my web page. http://linux.bbn.com/~koolish