| 21. | This involved the taking and measurement of 1400 photographic plates.
|
| 22. | Before CCDs, photographic plates were a common method of observation.
|
| 23. | Or do we still use photographic plates or click detectors on tracks for YDSE's?
|
| 24. | On 9 December he made a sequence of superb photographic plates of the event.
|
| 25. | She became an expert on estimating magnitudes of stars from images on photographic plates.
|
| 26. | He found that something came through, that would expose photographic plates and cause fluorescence.
|
| 27. | These expeditions obtained 350 photographic plates for the 1874 transit.
|
| 28. | On his death in 1900, he left approximately 360, 000 carefully preserved photographic plates.
|
| 29. | Until 1970 it had taken over 4, 000 photographic plates.
|
| 30. | Displacements of 1 / 1000 of a fringe could be measured on the photographic plates.
|
