Let's try and narrow it down by taking the earlier types in turn..
Blackburn First Monoplane (1909) - single-engine, single-seat high-wing monoplane aircraft
- not this one as the picture is clearly mid-wingedBlackburn Second Monoplane (1911) - single-engine midwing monoplane aircraft
- doesn't look like this one, the dihedral looks to be too flat and this type has a much more primitive lookBlackburn Mercury (1911) - single-engine, two-seat midwing monoplane training aircraft
- all the photos I can find show double-wheel undercarriage, but there were several variations on this type Blackburn Type B (1912) - single-engine, two-seat midwing monoplane training aircraft. A development of the Blackburn Mercury
- I can't find any pictures of this one but as a derivitave of the Mercury it seems unlikely as the Mercury had radically different undercarraige to the aircraft in the pictureBlackburn Type D (1912) - single-engine single seat mid-winged monoplane -
- the undercarriage configuration is wrong based on available photosBlackburn Type E (1912) - single-engine, midwing metal-framed monoplanes, one single seater one twin -
not this one as the undercarriage configuration and the engine type are wrong.Blackburn Type I (1913) - single engine 1/2 seat mid-wing monoplane built both as land- and seaplane
- the undercarriage configuration is wrong based on photos and plansBlackburn White Falcon (1916) - single engine two seat mid-wing monoplane
- the available photographs show a 4-bladed propI don't think this is a Blackburn, it looks like a continental design to me, either French or Italian, maybe German. The obvious SM reference would be Savoia-Marchetti, but that name wasn't adopted until 1922 and judging by the fashions that is too late - and they produced floatplanes/seaplanes. This is proving an interesting mystery..