reading the 'flight' article in more detail, it all becomes clear now...
"Mr Carter" is in fact W.G. 'george' Carter, chief designer of the Gloster aircraft company.
the flying boat shown is a hypothetical design powered by two bristol mercury air-cooled radials, for comparison with the 'Dornier' flying boat shown here,
http://www.secretprojects.co.uk/forum/index.php/topic,4969.msg39498.html#msg39498
powered by two water-cooled 'W' engines, probably napier lions.
it should be also be remembered that george carter also designed the Short-Bristow Crusader schneider trophy racer, also powered by a mercury radial, and who's lobate wing planform is also echoed in the hypothetical flying boat illustrated here.
cheers,
Robin.