Sentence:  '' Whereas , a Bridge over Merrimack River , from the Land of Hon ' ble Jonathan Greenleaf , Esquire , in Newbery , to Deer Island , and from said Island to Salisbury , would be of very extensive utility , by <WSD>affording</WSD> a safe Conveyance to Carriages , Teams and Travellers at all seasons of the year , and at all Times of Tide . 
Meaning of the word marked with <WSD> tags:  be the cause or source of