The best known of the Dublin bell founders was, undoubtedly, Matthew O'Byrne of The Fountain Head Bell Foundry. Matthew Byrne had been a Chief Engineer in The Royal Navy. In 1840 he established The Fountain Head Iron Foundry in James's Street, Dublin. His son, Matthew W., changed his surname to O'Byrne. Bells by Matthew O'Byrne were cast and, where necessary, tuned in the foundry before being fitted with headstocks and other fittings. In 1887 the "M Byrne Patent Rotary Mounting" was patented. This was a cast-iron headstock with a tapered hole through which a tapered boss on the crown of the bell was inserted and bolted in place using the crown staple bolt: "we claim that [this] is the best in existence; in fact, it has no rivals….By slacking the nuts, the bell can be rotated…in a few moments, thus presenting a new striking face to the tongue to strike. This increases the life of the Bell beyond measure".