242 SPECIAL RESULTS IN THE TJRANOLOGICAL 



The first named of these later astronomers had the great 

 advantage ( 422 ) of observing the nebula in Orion, since 1834, 

 with a twenty-foot reflector at the Cape of Good Hope at 

 an altitude of 60, and of thereby improving still further his 

 earlier drawing of 1824 26 ( 423 ). The positions of 150 

 stars in the neighbourhood of 6 Orionis, chiefly from the 

 1 5th to the L8th magnitudes, were also determined. The 

 celebrated trapezium, which is not surrounded by any nebu- 

 losity, is formed of four stars of the 4th, 6th, 7th, and 8th 

 magnitudes. The 4th star was discovered (1666?) by 

 Dominique Cassini, at Bologna ( 424 ) ; the 5th (y') in 1826, 

 by Struve ; and the 6th (a') which is of the 1 3th magnitude, 

 by Sir John Herschel in 1832. The Director of the Obser- 

 vatory of the Collegio Eomano, de Yico, announced at the 

 beginning of the year 1839, that with his large refractor by 

 Cauchoix he had found three more stars inside the trape- 

 zium. These stars have not been seen by J ohn Herschel or 

 Bond. The part of the nebula nearest to the almost un- 

 nebulous trapezium, and forming in the front part of the head 

 the Regio Huygeniana,, is spotty in its appearance, of a 

 granular texture, and has been resolved into stars by the 

 giant telescope of the Earl of Eosse, and by the great 

 refractor of the Observatory of Cambridge, U.S. ( 425 ). 

 A.mong our modern accurate observers, Lamont at Munich, 

 Cooper in Ireland, and Lassell in England, have determined 

 many positions of small stars. Lamont employed a magni- 

 fying power of 1200. Sir William Herschel thought that 

 he had satisfactorily convinced himself, by the comparison of 

 his own observations made with the same instruments 

 from 1783 to 1811, that changes had taken place in 

 the relative brightness and in the outlines of the great 



