DETROIT – An 18th century British cannon retrieved from the Detroit River in October 2011 before undergoing a three-year restoration process was unveiled this afternoon and goes on display for the public this weekend at the Dossin Great Lakes Museum on Belle Isle.

Detroit Police Department divers first discovered the cannon in July 2011 and raised it a few months later in October. Then, Detroit Historical Society Senior Curator Joel Stone and the team at the Society's Collections Resource Center got to work. The cannon first went into wet storage until a conservation protocol was established with the assistance of maritime archaeologist Dan Harrison. I was given exclusive access to the cannon at this point, and you can see the story I did with some amazing close up video -- watch it here.

Follow me on Twitter: @PaulGrossLocal4

Find more stories like this at ClickOnDetroit.com/Thermoscope.

Restoration work commenced at the Cranbrook Institute of Science in 2013, where the cannon was put on public display for a special exhibit. An electrolysis bath drew harmful chemicals from the iron using an electrical current, and young visitors participated in several cleaning sessions. Once back at the Collections Resource Center, electrolysis continued for a year. Over the last two months, the barrel was dried with pure alcohol, and finished with a coating of tannic acid to stabilize the exterior iron.

During the restoration process, the cannon's past started to become clear. The barrel was embossed with the crest of King George II, who reigned from 1727-1760. Additionally, it was marked with a "P", an "X" and an "M." The "P" indicates approval from a civilian approval board, and the "X" is a failure mark by the military ordinance board; while the "M" stands for Mangles, the arms dealer that sold the cannon. On the right trunnion, an "H" was discovered by a group of children working with toothbrushes at Cranbrook. This represents the Hamsell Furnaces of East Sussex, England, where the cannon was manufactured by hand in the mid-1740s.

When the British abandoned Detroit in 1796, rather than leave outmoded armaments to the Native Americans or Americans, troops were ordered to destroy them. From the fort, soldiers moved the cannon down to the riverbank, near the site of present-day Cobo Hall. Speculation suggests that they slid this gun, along with five others, onto the winter ice. When the ice thawed, the cannons sank, where they remained for more than 200 years.

You can see the cannon up close and in person at the Dossin Great Lakes Museum, which is located at 100 Strand Drive on Belle Isle. The museum is open Saturdays and Sundays from 11 a.m. to 4 p.m.

Admission is free!