Magnifying Powers of Eye-Pieces and Objectives.
A TYPICAL AND INITIAL SELECTION OF POWERS OF EYE-PIECES CALCULATED FOR THE 10-INCH TUBE-LENGTH.
| Name | A | B | C | D | E | F | ||
|---|---|---|---|---|---|---|---|---|
| of Maker. | 0 or No. 1 | 2 | 3 | 4 | 5 | 6 | ||
| Baker | 6 | 8 | 12 | 15 | — | — | Diameters. | |
| Beck, R. & J. | 4 | 8 | 15 | 20 | 25 | not made. | " | |
| Leitz | 5 | 6 | 7 | 8 | 10 | 12 | " | |
| Powell & Lealand | 5 | 7·5 | 10 | 20 | 40 | " | " | |
| Reichert | 2·5 | 3·5 | 4 | 5 | 6·5 | " | " | [24] |
| Ross | 3 | 8 | 12½ | 20 | 25 | 40 | " | [25] |
| Swift & Son | 6 | 9 | 12 | 15 | 18 | 21 | " | |
| Watson & Sons | 4 | 6 | 8 | 10 | 12 | 15 | " | |
| Zeiss | 3 | 4 | 5·5 | 7 | 9 | not made. | " |