Large rockets as an alternative to early torpedoes

What could replace the torpedo as an early twentieth-century destroyer's anti-capital-ship weapon?

Large rocket-propelled explosives are the suggested alternative, drawing on late nineteenth-century projectile work.

The question suggests an improved Vesuvius-style gun as a destroyer's weapon against capital ships. The answer instead points to rocket-propelled explosives. It recalls work on 12-inch rockets in the 1880s and 1890s, and designs for even larger projectiles. The possibility is that greater development effort could have produced usable rocket ships by the First World War if torpedoes had failed. The remembered museum records have generic projectile-system names, so no precise project designation is supplied.