In the directory chronicle for China and Japan from 1894, page 124, I found a list of employees working for Hall & Holtz in Shanghai:
1) Allen, J.W., assistant, Hall & Holtz, Shanghai,
2) Bowness, S., assistant, Hall & Holtz, Shanghai,
3) Bryan, J.S., assistant, Hall & Holtz, Shanghai,
4) Byrne, E., manager, Hall & Holtz, Shanghai,
5) Carion, B., assistant, Hall & Holtz, Shanghai,
6) Carion, F.F., assistant, Hall & Holtz, Shanghai,
7) Cook, E., assistant, Hall & Holtz, Shanghai,
8) Colgan, E.J., assistant Hall & Holtz, Shanghai,