Field Artillery Weapons of the Civil War by James C. Hazlett, Edwin Olmstead, M. Hume Parks pp.196,197
"Flanking the porch steps leading up to Quarters H at Washington Navy Yard are two undersized iron rifles. Their shape at the breech is essentially conical, with striking family resemblance to that of recognized Blakely types 2, 5, 6, and 7. Despite challenges to their authenticity, or lack of visible stampings, but because of their shape, kind of rifling, and drilled vents, Warren Ripley considered them genuine contemporary weapons and assigned to them the tentative identification, Blakley rifles, type 10. A third survivor has since been found, privately owned. Its right hand trunnion is stamped: BLAKELEY LONDON we decline to speculate about the extra e in the name Blakley but agree that it is reason for further factfinding if possible.
These little rifles appear to have separate pressed on trunnion bands, like Blakely types 4 and 6. Whole length is 36.75 inches with maximum swell of the reinforce of 6.44 inches. The bore is 29.75 inches long, with six sawtooth rifling grooves of right hand twist, 2.9-inch land diameter and 3-inch groove diameter. Ripley has pointed out that these pieces should be interchangeable in the carriages of regulation mountain howitzers."