That would be 1864, not 1846. I expect you saw the stone at Bride noting his age, 4½ months. He is commemorated with his great-grandparents, Charles Joughin, Ballagenny, d Ramsey 5 Dec 1831 aged 50, and Margaret his wife, d 11 Feb 1867 aged 80. I have the family of Charles Joughin, if you are interested in this line.
I also have a jotting made by my father some years ago on a ticket folder for the Mananan Festival Port Erin. It recites William Henry Forshaw, son of Mary Ann Sutherland, who was the daughter of Mary [should be Margaret] Joughin of Bridge Inn Ramsey. Her mother was [blank] son of John Joughin of Ballagenny, died 1818. There is a note of a Miss Ruby Forshaw with an address in Colby, with sister Lillian Paterson. The information would appear to emanate from Joyce Halliwell.
If you are interested in any of this, please e-mail me at pjallen@btinternet.com for further information.