In 1922, Professor Hugo Michnik, invented the bifilar sundial. In the original version, the bifilar sundial has two non-touching threads parallel to the horizontal dial. The second thread is orthogonal to the first. The intersection of the two threads’ shadows gives the local apparent time.

Michnick’s bifilar sundial (Wikipedia)

In sundial proposed here, the table is declinining and inclined, and threads are non-parallel to the table and non-perpendicular each other.

BSS comp EM threads

The threads: non-singular positions

BSS comp EM table

The table: declining & inclined

This dial is designed with an original software (HUGO, in homage to Professor Hugo Michnik) described in two French-language papers published in “Cadran-Info” (co-author: Dominique Colin).


M.E_C.D_Logiciel bi filaire

M.E_C.D_Logiciel HUGO

Note: The software version used here is newer and better than the one described in papers because it takes into account the threads length.

BSS comp EM lines

Software output: grey lines are hour lines position in the case of threads became longer.

BSS comp EM sundial table

The sundial table

BSS comp EM dates 1

October 11, 11h30 (TU+2) threads shadows in red

BSS comp EM dates 2

October 12, 12h00 (TU+2) threads shadows in red

BSS comp EM dates 3

October 12, 13h00 (TU+2) threads shadows in red

No cross !

BSS comp EM dates 4

October 11, 15h00 (TU+2) threads shadows in red

Cross is back !!

BSS comp EM dates 5

October 12, 16h00 (TU+2) threads shadows in red

BSS comp EM dates 6

October 12, 17h00 (TU+2) threads shadows in red

Sorry, no more sun in this place, in October !

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