Hello Louise, 
These are the John Dinsmores listed in 
 Griffith's Valuation of Donegal  which took place in 1857. 
John Dinsmore, Tobernahoory, Drumhome, Donegal 
John Dinsmore, Main Street, Ballintra, Drumhome, Donegal 
John Dinsmore, Ballyruddelly, Lismintan, Drumhome, Donegal 
John Dinsmore, Lacklom, Drumhome, Donegal 
John Dinsmore, Grahamstown, Drumhome, Donegal 
John Dinsmore, Ballintra, Drumhome, Donegal 
I'm not certain whether this is a listing for one guy owning a lot of properties or several guys with the same Christian name. 
Christopher