| Listed in probable order of formation. These entities are currently in the research queue. |
| Manufacturer of incandescent lamps. Possibly the first business Green became involved with in Hartford; his initial relationship with this business isn’t clear, but he did eventually own it. Also appears to be how he met John Bauer, who had been employed by Aetna Electric Company as a glassblower. One known location at 356 or 366 Asylum Street. |
| Manufacturer of incandescent light designed by Henry Green. Company formed with financial backing of W. F. Henney, George S. Miller, and W. N. Woodruff. First product was incandescent lamp designed by Green. No known address. |
| Manufacturer of devices related to x-rays. Also known as Green & Baur, Greene & Bauer. Formed by Henry Green in partnership with John Bauer, uncertain when. Three known locations: 33 Wells Street, 38 Ann Street, and 234 Pearl Street. |