Which preposition to use with mechanician

in Occurrences 2%

"The inventor must seek and employ the skilled mechanician in his workshop to put the invention into practical form, and for this purpose some pecuniary means are required as well as mechanical skill.

from Occurrences 1%

Down below the transmission gearing gets out of order, and this prevents the mechanician from sending the trap up again.

of Occurrences 1%

Go to Delsarte here, and learn even from the mechanician of smiles that a smile can be indicated by a movement of muscles so slight that neither instruments nor terms exist to measure or state it; in fact, that the subtlest smile is little more than an added brightness to the eye and a tremulousness of the mouth.

Which preposition to use with  mechanician