588 The Smithsonian Institution 



satellites, and devotes special sections to a modification 

 of the nebular hypothesis of Laplace, and to a modifica- 

 tion of Jones's theory of the zodiacal light. The memoir con- 

 cludes with a summary of the coincidences between theory 

 and fact. 



COMETS 



IN the early years of the activity of the Institution the dis- 

 covery of comets was rewarded, or, as it is better to say, com- 

 memorated, by the award of a gold medal founded by the 

 King of Denmark. 



Miss Maria Mitchell, of Nantucket, 1 discovered a comet 

 on October i, 1847, which was independently discovered in 

 Europe by Da Vico (October 3), Dawes (October 7,) Madame 

 Rumker (October 1 1), and which was known as Da Vice's 

 comet for some time, owing to the slow mails of those days. 



To mark the fact of her discovery, the Institution gallantly 

 awarded a premium to Miss Mitchell, but the precedent so 

 set was not followed in subsequent discoveries by her male 

 rivals Bond, Van Arsdale, Tuttle, and others. Miss Mit- 

 chell subsequently became a computer for the "American 

 Ephemeris," and the gallantry was continued by assigning to 

 her all the calculations relating to the planet Venus. The 

 account of Miss Mitchell's discovery is given in the second 

 volume of the "Contributions." 



COMET-ORBITS 



IN the Report for 1862 is a most interesting letter from 

 Professor Hubbard, of the Naval Observatory, describing his 



1 Miss Mitchell was professor of astronomy in Vassar College from 1865 till 1889. 



