The Old Town canoe with serial number 21836 is a 16 foot long, CS grade, HW (Heavy Water) model with red Western cedar planking, closed spruce gunwales, birch decks, ash thwarts, spruce outside finish rails, a keel, sponsons and painter ring. It was built between April and May, 1912. The original exterior paint color was dark green with a name on the right and left bow. It shipped on June 5th, 1912 to Harrison, Maine. A scan of this build record can be found by following the link at the attached thumbnail image below.
This scan and several hundred thousand others were created with substantial grants from the Wooden Canoe Heritage Association (WCHA) and others. A description of the project to preserve these records is available at
http://www.wcha.org/catalogs/old-town/records/ if you want more details. I hope that you will join or renew your membership to the WCHA so that services like this can continue. See
http://www.wcha.org/wcha/ to learn more about the WCHA and
http://www.wcha.org/join.html to join.
The Old Town canoe with serial number 24836 is 17 feet long and did not have sponsons.
It is also possible that you could have another number or manufacturer if this description doesn't match your canoe. Feel free to reply here if you have any other questions.
Benson