In George the Third's collection of tracts, now in the British Museum, is
a broadside of one page, commencing thus:--"In the name of God, amen! John
Bulmer, of London, esquire, Master and Surveyor of the King's Majesties
Mines, &c. &c. propoundeth--by God's assistance, that he the said John
Bulmer, shall and will, at and in a flowing water, set out a boat or
vessel with an engine, floating with a man or boy, in and on board the
said boat, in the River of Thames, over against the Tower-wharf, or lower.
Which said boat, with the said man or boy, in or aboard her, shall the
same tide before low-water again, by art of the said John Bulmer, and help
of the said engine, be advanced and elevated so high, as that the same
shall pass and be delivered over London Bridge, together with this said
man or boy, in and on board her, and float again in the said River of
Thames, on the other side the said bridge in safety." He then proceeds to
covenant for himself, his heirs, &c., to perform this within the space of
one month, &c., or so soon as the undertakers, wagering against him six
for one, should have deposited in the assurance office such a sum as he
should consider sufficient to countervail his charges of contriving the
boat and engine. Captain Bulmer was also to deposit his proportion of
money, &c. This scheme was brought out in 1643.