Antique John Bliss & Co. Gyro Compass

Up for auction is a very nice antique John Bliss & Co. ships gyro compass.  In good condition for its' age.    The compass is marked "JOHN BLISS & CO. NEW YORK".     I am guessing this was mounted on some sort of platform.

Approx  8 1/2" in diameter.  Please see photos. 

I am not expert on boat parts so please ask questions prior to bidding and I will answer the best that I can.