The diptych was made by Thomas Ducher. Sent from my iPhone
On Aug 10, 2018, at 12:48 PM, Michael Ossipoff <[email protected]<mailto:[email protected]>> wrote: Yes, the Boy Scouts of America at least used to sell a Compass-Oriented Dyptich dial with several concentric rings, each having different hour-lines, and with its string-gnomon adjustable for latitude, with several attachment-points on the vertical surface. I think it accommodated 3 latitudes. The hour-line rings were rectangular, it seems to me. Someone at this forum designed a universal Horizontal-Dial whose hour lines were curved lines originating from the gnomon-string's base-attrachment, with latitude-labeled concentric circles telling where to read the hour lines for the various latitudes. ...and of course with the string-gnomon slidable in a vertical slot in the vertical surface. Michael Ossipoff On Fri, Aug 10, 2018 at 4:22 AM, Dan-George Uza <[email protected]<mailto:[email protected]>> wrote: Dear all, I've recently found this piece in a museum near me and I need your help in dating it. Why are the hour marks offset? I suspect a correction for latitude. And what do the two small circular dials on the bottom measure? Also what would be the purpose of the circular shape containing the alidade? I suspect it has something to do with the winds. Any info will be highly appreciated. Thank you, Dan Uza --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial<https://urldefense.proofpoint.com/v2/url?u=https-3A__lists.uni-2Dkoeln.de_mailman_listinfo_sundial&d=DwMFaQ&c=WO-RGvefibhHBZq3fL85hQ&r=7ZsgDX5inZSMERqhZEQacOtdADP0iy6-YB7dx6Z_mVo&m=3-DALhUvBQJn8P9cKR9FHS3EG06h7iYhIPEnqd_W0kI&s=ifZ07QqBi_JWsaekGzvK_IWYmTdGpp6kYF_t_p0_shI&e=> --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
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