Belgian brand Minerva hasn't featured on this blog before so here to rectify this is the below photo. I would put the date of the bike as circa 1905 - the Minerva v twin was introduced in 1905 and this one has a trembler coil rather than magneto. The bike seems to have been modified as the pedal gear has been removed and footboards fitted.
For an excellent history of Minerva motorcycles check the Minerva Motocyclettes 1900 - 1909 site.
|c 1905 Minerva v twin.|