American inventor who in 1775 designed a man-propelled submarine that was ineffectual but subsequently earned him recognition as a submarine pioneer (1742-1824)
अमेरिकी आविष्कारक ने 1775 में एक मानव-विकसित पनडुब्बी तैयार की जो कि बेपरवाह थी लेकिन बाद में उसे एक पनडुब्बी अग्रणी (1742-1824)