The tubelock is credited to the famous English gun maker Joseph Manton who was the gun maker to the well known sportsman Col Peter Hawker ,if you read volume 1 and 2 of his diaries he mentions both Joseph Manton and Alfred Clayton has gunmakers both made Tube lock guns
The tubelock was prior to the percussion cap and dates from 1810 ,the lock parts were has follows ,the hammer instead of a nose was fitted with shield and what is known has a spade {see image} ,some of the large bore fowling guns hammers were fitted with a shield on the side ,this was to prevent the tube from blowing out when ignited . The barrel instead of a pan had what is known has a anvil on this was placed the tube which was a hollow piece of copper sealed at one end ,filled with a fultimate compound and inserted into a touch hole.When the hammer struck the tube it ignited the fultimate which fired into the touch hole and ignited the main charge, ignition is just has quick has the percussion cap
Feltwad
A Flint Lock will not secure a chicken house door