| This hand-driven generator was made by Palmer & Hall of Boston, but the date is not known. Turning the wheel rotates two coils wound about iron cores which are at the ends of a horseshoe permanent magnet |
 |
|
|
|
|
|
| This hand-driven generator was made by Palmer & Hall of Boston, but the date is not known. Turning the wheel rotates two coils wound about iron cores which are at the ends of a horseshoe permanent magnet |
|
|