Mystery solved......

I have just recieved this reply from the National Portrait Gallery re. the mysterious object in the portrait(see "Another World..... below).

"I believe this fitting to the Earl’s armour is a lance-rest, used when tilting. As painted, the rest is upright, but in use could hinge down through 90 degrees and serve as a support to the butt end of the lance. This lance-rest is rather ornamental; others have a much plainer and more overtly functional form."

And we thought it was for carnations!!!!!