 | Francis Rolt-Wheeler - 1909 - 358 pages
...the flocculent appearance of the photographs." "With the spectroheliograph," Professor Hale relates, "it was at once found possible to record the forms,...brilliant clouds of calcium vapor associated with the faculas and occurring in the vicinity of the sun-spots, but also of a reticulated structure extending... | |
 | 1904 - 596 pages
...ordinary photographs, like the one in Fig. 4, or to the eye when observing the sun through a telescope. The results of the first experiments, which were made...brilliant clouds of calcium vapor associated with the facula?, and occurring in the vicinity of sun-spots, but also of a reticulated structure extending... | |
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The calcium regions above referred to are usually associated with the faculae, but they lie above them, and they give no trace of their existence on ordinary photographs, like the one in Fig. 4, or to the eye when observing the sun through a telescope.... 