As shown below, Volume 11 of the 1842 book "Encyclopedia Britannica or Dictionary of Arts, Sciences, and General Literature" (seventh edition) states, "nothing appears externally on the lock-plate but the cock or striker, which gives the blow to the copper cap when the gun is fired, and which is hollow or concave, provided also with a small ring of projecting metal, called a shield or fence, running round the cock at the bottom of the concave head, to defend the eye from the splinters of the copper cap, and the small stream of fire that issues upwards from the hole in the nipple when the gun is discharged. Serious accidents happened at first from the use of detonators, by not adopting such precautions. At first the heads of the cocks or strikers of copper-cap guns were not made hollow or concave, and without any shield or fence round them to protect the eye, but were made plain or smooth, like the head of an ordinary carpenter's hammer: the consequence was, that when the copper cap flew into pieces when struck, the eye of the sportsman was frequently injured, and sometimes totally destroyed, by such accidents."
As shown below, the July, 1832 issue of "The New-England Magazine" states, "The fragments of a percussion cap usually fly in all directions, thereby endangering the eyes of the gunner and his companions. This difficulty is easily obviated. Let the hammer of your lock be well hollowed, and it will confine the pieces of the shattered cap, or give them a downward direction. Thus, hide your irregularities, and they will do you little harm."
As shown below, the 1833 British book "A Treatise on the Progressive Improvement & Present State of the Manufactures in Metal" states, "In the explosion, the copper cap is torn — sometimes divided and projected; but by hollowing the head of the percussion hammer, the copper is no longer projected except towards the ground."
As shown in the excerpt below, the 1845 Scottish book "The Sportsman's Library" states, "Many protections have been invented, to save the eye from the flying particles of the cap: but none are so effectual as a sloping nipple, with a strong, thick copper cap, and a deep concave-headed cock to cover it."
The following excerpt from the December, 1830 issue of the "American Turf Register and Sporting Magazine" states, "Mr. Gist, while shooting, received an injury in the forehead by the percussion cap flying off. We understand that lately an opening has been made in the front of the hammer that falls on the nipple, to let off any pieces of the cap."
The following page is from the 1827 British publication "The Sporting Magazine". It makes reference to a percussion cap-related eye injury with a "plain hammer" and several percussion cap-related injuries with locks "of the best patterns". Although not included here, I have seen plenty of medical literature from the 1800s that describes percussion cap-related eye injuries.
L. Dietle
