Joseph James Speed was a mechanical engineer from Waltham Cross, Hertfordshire, who registered a number of arms patents in 1887 and 1888:

Pat.No. 6335; 30/04/1887
Magazine cut-off for single loading.

Pat.No. 13,335; 01/10/1887
Improvements to the Lee Rifle, specifically butt-stock, bolt-head, extractor, bolt-cover, and long-range sight.

Pat.No. 17,944; 13/12/1887
Magazine spring

Pat.No. 15,786; 01/11/1888
More improvements to the Lee rifle, ie safety catch, detachable hand-guard, disposable magazine, and double-column magazine.

Many of Speed's patents remained in manufacture for perhaps 80 years, a remarkable achievement! Despite this, only the commercial variant of the Magazine Lee Enfield, dubbed the 'Lee Speed', bears his name.

I assume James Paris Lee needs no such introduction here!