 In around 1770 the neoclassical architect Robert Adam designed Pulteney Bridge , a three @-@ arched bridge spanning the River Avon . He used as his prototype an original , but unused , design by Andrea Palladio for the Rialto Bridge in Venice . Adam also submitted plans for the new Assembly Rooms but these were rejected as too costly . John Wood , the Younger raised funding for the construction of the Assembly Rooms by the use of a Tontine , an investment plan that is named after the Neapolitan banker Lorenzo de Tonti , who is credited with inventing it in France in 1653 . It combines features of a group annuity and a lottery . Each subscriber pays an agreed sum into the fund , and thereafter receives an annuity . As members die , their shares devolve to the other participants , and so the value of each annuity increases . On the death of the last member , the scheme is wound up . Construction started in 1769 and was completed in 1771 , when a grand opening was held . 
 In around 1770 the neoclassical architect Robert Adam designed Pulteney Bridge , a three @-@ arched bridge spanning the River Avon . He used as his prototype an original , but unused , design by Andrea Palladio for the Rialto Bridge in Venice . Adam also submitted plans for the new Assembly Rooms but these <a href='uninflect' title='1'><mark>were</mark></a> rejected as too costly . John Wood , the Younger raised funding for the construction of the Assembly Rooms by the use of a Tontine , an investment plan <a href='null_relcl' title='2'><mark>that</mark></a>is named after the Neapolitan banker Lorenzo de Tonti , <a href='null_relcl' title='3'><mark>who</mark></a>is credited with inventing it in France in 1653 . It <a href='uninflect' title='4'><mark>combines</mark></a> features of a group annuity and a lottery . Each subscriber <a href='uninflect' title='5'><mark>pays</mark></a> an agreed sum into the fund , and thereafter <a href='uninflect' title='6'><mark>receives</mark></a> an annuity . As members die , their shares devolve to the other participants , and so the value of each annuity increases . On the death of the last member , the scheme <a href='drop_aux' title='7'><mark>is</mark></a>wound up . Construction started in 1769 and was completed in 1771 , when a grand opening was held . 
In around 1770 da neoclassical architect Robert Adam designed Pulteney Bridge , a three @-@ arched bridge spanning tdaRiver Avon . He used as his prototype an original , but unused , design by Andrea Palladio for thdaialto Bridge in Venice . Adam also submitted plans fa the new Assembly Rooms but these was rejected as too costly . John Wood , the Younger raised funding for the construction of the Assembly Rooms by the use of a Tontine , an investment plan is named after thedaapolitan banker Lorenzo de Tonti , is credited with inventing it in France in 1653 . It combine features of a group annuity and a lottery . Each subscriber pay an agreed sum into the dad , and thereafter receive an annuity . As members die , their shares devolve to the odar participants , and soo the vada of each annuity increases . On the death of the last member , the scheme wound up . Construction started in 1769 and was completed in 1771 , when a grand opening was held .