This is a great early Mordan pencil. The “S. Mordan & Co. Makers” signature was used from 1845-1852. Mechanically it is fine . Some wear to the barleycorn design from the slider. Nice clear yellow (citrine) glass “stone” in finial. Finial unscrews to reveal 3 inner tubes for spare lead.
"S. Mordan & Co. Makers"