I wonder if anyone can help me find out the age of my historic house in port washington, NY. It was a farmhouse later converted to an estate residence. While doing a small renovation this summer on the entry, I uncovered an older beam and post construction on the section where the farmhouse was. It is a mortice and tenon framing in heavy timber with a wooden peg thru the joint. also, each joint is marked with roman numerals chiselled into each piece of the joint.The timber looks like a dense pine of some sort. The farm was sold in 1900 and I wonder if the post and beam structure dates from before or after this time.