try http://www.manxnotebook.com/famhist/genealgy/index.htm - that will give you some start
1887 means that you can get a copy of his birth cert from IoM General registry
and determine Parents - after that census info will take back to 1841 - prior to this parish records (though the 1780-1840's can be a pain) - with some luck combination of parish and land holding records take you back as far as 1511 - before that it tends to be guess work!
ps - it is Santon (Santan or in 18th C StAnne parish) - newtown itself was a putative development from 1720's - was going to be a 'new town' but little came of it except a few houses and what is now known as Mount Murray.