The safety-catch Titan was the "Mark 7", the last and the best in the Titan series. It is difficult to date when each model was introduced exactly (except the first, in 1916), as they were introduced over a relatively short period (about 1918 to 1923) when Frank Clarke was constantly refining his design, and there are very few illustrated adverts to help date them. There would also have been a lot of overlap when two (or even more) versions were probably being sold at the same time. The best estimate at present is that the Mark 7 was first on sale in about 1923 and was sold up until about 1926.

If anyone knows of any old adverts or dated catalogue pictures of Titans I would love to hear from you, so that the history of these designs might be pinned down a bit more accurately.

Yours in hope,
John