The 1861 Hunt, Barry & French Instruction for Field Artillery manual states:
"Personnel. The number of men required for the service of a battery, including non-commissioned officers and artificers, varies from twenty to thirty per piece, according to circumstances: the number for field service should never be less than twenty-five, even in 6-pounder batteries. They should be intelligent, active, muscular, well-developed, and not less than five feet seven inches high; a large proportion should be mechanics. The number of officers varies from four to six, depending on the number of pieces in the battery. "
From my research a artificer at this time in military history is anyone in the battery that has a specialized job, ie: blacksmith, farrier, leatherworker, etc... They may have been named per se in later periods, but for now they were grouped under artificer. Basically, a skilled worker.
I did have a citation from another period manual that states the above, but right now it is avoiding me. I will post when I find it.
Best of luck.
Your obedient servant,
Iron City Guards
(1st PA Light Art'y- Bt'y G / 9th PA Res. - Co. C)
"Sole purveyor of the finest corn silk moustaches as seen in the image above, adhesive not included"