About the different historical calenders. This calendar handles the change from Julian to Gregorian calendars in different countries.
How a flintlock pistol works. With slow motion animation.
The inventory of English royal ordinance in 1637.
The formula to explain underwater sound propagation.
OK so the person who put all that on a website is a military nutcase, but he didn’t know about this. The Australian Army Artillery Museum on North Head, Manly.