He killed himself after the death of his romantic and stage partner Gladys Horridge coincided with the imminent exposure of his deceptions about their marital status.

[10] Henry also appeared as the subject of a comic strip in the Daily Sketch,[5] and Clapham wrote in character for The Radio Times[11] and Tit-Bits.

"An inquest, held by the coroner for Paddington, Ingleby Oddie on 16 May, gave a verdict of death from coal gas poisoning, and that Clapham "killed himself while of unsound mind".

[13] During the inquest, it emerged that Clapham had feared that the exposure of and prosecution for his pretence of being married to Horridge would harm his career, and that he was being pursued by his estranged wife for alimony.

[13][15] Around 500 mourners attended his funeral, at Streatham Park Cemetery, which was paid for by the Variety Artistes' Benevolent Fund.

[5] Jennifer Purcell of Saint Michael's College called him "the first artist to write and perform radiogenic material.

"[2] She noted his experimental use of sound effects, and called his style as "warm and conversational, with a sense of casual armchair intimacy, well-suited to the domestic space of radio listening".

[2] However, she also critiqued how he "delineated the collective identity of his audience with remarks aimed at married men and fathers", giving as an example his comparison of wives to loudspeakers.