Back in the 1800s (or maybe early 1900s) an enterprising gunsmith created this French Mod. 1873/74 revolver. The trigger has been turned into a sear which is manipulated by squeezing a steel rod. It i Very clever. Note the other details such as the de-spured hammer.
More info and photos at LittleGun.be (thier English translation is very poor).
[ Many thanks to Todd for emailing me the link. ]Related