THE SUN. 55 



Lorenzo Respighi (1824-1889), emdPietro Tacchini 

 (1838-1905). After the death of Secchi, the 

 recognised head of spectroscopy in Italy was 

 Pietro Tacchini. Born at Modena in 1838, he 

 was appointed director at Modena in 1859, 

 assistant at Palermo in 1863, and director at 

 Rome in 1879. In 1870 he commenced to take 

 daily observations of the prominences, noting 

 their sizes, forms, and distribution, and these 

 observations were continued for thirty-one years, 

 until within four years of Tacchini's death, which 

 took place on March 24, 1905. Tacchini did 

 for the study of the prominences what Schwabe 

 did for the spots. The Italian spectroscopists 

 found that the prominences increased and de- 

 creased every eleven years in harmony with 

 the spots. Tacchini demonstrated that the 

 streamers of the solar corona originate in 

 regions where the prominences are most numer- 

 ous, and that the shape of the corona, on the 

 whole, varies in sympathy with the prominences. 

 The researches of Lockyer indicated that the 

 prominences originated in a shallow gaseous 

 atmosphere which he termed the chromosphere. 

 Formerly astronomers had to observe only 

 isolated prominences, but in 1892 an American 

 astronomer, George Ellery Hale (born 1868), 

 formerly director of the Yerkes Observatory, 



