Horizontal Inclining Sundial by T. Mason Dublin, c.1808-1813

Encased, Portable Horizontal Inclining Sundial by Thomas Mason, in original embossed, hand-stitched leather case. Irish made, circa 1808-1813. Signed 'T. Mason Dublin'.

Thomas Mason (1781-1837) was an Irish optician & scientific instrument maker who apprenticed under his father, Seacombe Mason (1745-1804), alongside his brother Jason until their Seacombe's death in 1804. From 1805-1808, the brothers partnered under the trade name 'T & J Mason'.

Trading under the singular 'T. Mason' would have been possible only from 1808-1813, after which Thomas & Jason resumed their partnership, reviving the 'T & J Mason' signature. They continued with the family business throughout their lives before handing the reigns to Thomas' son, Seacombe Mason (1808-1892). Thomas Mason served as Optician to His Excellency the Lord Lieutenant before his death in 1837.

This piece features an adjustable horizontal dial with a 60-degree gnomon base-angle. Compass card has 8 cardinal directions with a jeweled pivot and needle lock. The dial is graduated every 1-degree with quadrants graduated every 10 degrees. A very rare individually signed piece from a dynasty of renowned opticians.

Later model featured in Harvard University (Collection of Historical Scientific Instruments)