How Long Is “Naval Attack on Portsmouth”?

A battle between two forces takes place. There's no information on this 4-minute film aside from the fact that it was available from Charles Urban's Urban Trading Company, one of the most vigorous of British film production and distribution companies in the era. It's a well-composed and edited piece for 1907. The uniforms of the opposing forces, one in dark uniforms and one in white, under battle standards with the Union Jack look good. The field pieces and the medics transporting the wounded are likewise believable, although the compositions, if anything, look too good for it to have been war games; likewise, the smoke from the artillery obscures the action.