The lenses have been known to stop flying shrapnel from entering the eyes of our troops.
Rifled guns with shrapnel shell were considered more than sufficient to make good the slight advantage then conceded to the breech-loader.
Large pieces of shrapnel were stuck inside.
The "Intrepid" astern had come under heavy shrapnel fire from the guns as she approached the mole, but after rounding it escaped their attention.
She came under shrapnel fire off the mole, and as she rounded it a star shell showed up the "Intrepid" heading for the canal and the "Thetis" aground.