Engineer a pretty broad term. Did you look him up to see what field of Engineering he graduated in?
He didn't graduate from the University of Glasgow. There are lots of versions of 'engineer' that don't involve graduation.
There is an Electrical Engineer in Antrim also a Adam that died there in 1902 (don't know if they are one in the same).
There were two deaths of Adam Hamiltons of roughly the right age in Ireland, a farmer in Belfast in 1902 and a carpenter in 1906. From the 1901 census the farmer was born in Antrim. I can't find a matching carpenter as such in 1901, but there is an Adam Hamilton, millwright, aged 56, which must be him, also born in Antrim.
There is an Adam age 38 who arrived NYC in 1888 on the Aller from Bremen. Has a German spouse and young child.
I saw the ariival of an Adam Hamilton, 38, merchant in 1888, but have not been able to find him in any later census to check his birthplace. There's also a death of a child, daughter of Adam Hamilton, born Scotland, in Massachusetts in 1894, but again I have not found this Adam in a later census.
I can't look for a leter death in NI because the GRONI web site seems to be misbehaving.
Any idea what Cleland died of?
No. I looked for a death certificate but have yet to find one.