8 REPORT 1866. 



F. 5tli union of two units, forming part of bodj' Ci, wliicli is tlie fourth pcut of 

 cube. 



Ct consists of 3 units, forms one-fourtli of cubej and is the body obtained by 

 the third mode of dividing tlie cube. 



II. Cube composed of 4 of the above bodies, G. 



I. Four of the same bodies (G) reversed and rearranged to produce the half of 

 the rhomboidal dodecahedron. Another cube simihirly divided and arranged com- 

 pletes the solid. 



J. Six units or three of C so arranged as to produce the rhomboidal ntbe—^ibe 

 basis of the hexagonal system. Seven of these bodies build up the bee's cell. 



K. The cube divided by cutting off four three-sided pyramids, leaving a tetrahe- 

 dron in the centre. The four three-sided pyramids cut oft' may be so arranged as to 

 produce the half of the true octahedron. 



L. Rhomboidal dodecahedron VN-ith pyramids (C) on each of the tweh-e faces. 

 This body contains forty-eight miits (A). 



]M. The remainder of the large cube having a side of 2 inches, consists of foi-ty- 

 eight units (A) so arranged as to show how the rhomboidal dodecahedron (L) can 

 be inserted in the vacant space. 



Astronomy. 



HemarJcs on the Variable Star lately discovered in Corona Borealis. 

 By J. R. Hind, F.R.S. 



Early in June last the author received a letter from Mr. W. Barker, of the Customs 

 Department, London, Canada West, stating that the remarkable variable star in 

 Corona Borealis, which was seen in Europe on May 13, had been discovered by him 

 on the 4th of that month. He thus descriljes its variations : — " I first observed it 

 on the 4tli of May at 9 p.m., when it was somewhat brigliter than Epsilon Coronaj ; 

 it rapidly increased until the lOtli, whenit was fullj- as bright as Alphacca (Alpha 

 Coronte) ; it was at its maximum. On the 14th it had decreased to the third 

 magnitude, on the 18th to the fifth. On the 19th I could just discern it, and on 

 the 20th 1 could see it no longer with unaided vision. On the 20th I observed it 

 through my telescope (one of Cooke's 5 feet 4 inch object-glasses). With a power 

 of 133, it showed a beautiful clear disk, and was exceedingly brilliant, and had a 

 ruddy tinge. I still see it as a telescopic star ; its light about equal to the com- 

 panion of Polaris." As far as the author was at present informed, Mr. Barker did 

 not make a public announcement of his discovery until the 16th of May, when he 

 communicated a paragraph to the ' London Free Press,' and forwarded copies of 

 the paper to various astronomers in this country. It rims thus : — " Asti'onomers will 

 be interested to learn that a new .star has made its appearance in the constellation 

 of Corona Borealis. It is of the third magnitude, and is situated about one degree 

 S.E. by E. of Epsilon Corona", and three degrees from Pi Ophiuclii, in a direct line 

 between the two. It also forms the apex of an equilateral triangle with Beta and 

 Zeta Ilerculis. Hour of observation, 9 p.m., 14th May, at London, C.W." It will 

 be remarked that in this communication no reference is made to any observation of 

 the star previous to the 14th of May,-probably because Mr. Barker merely intended 

 his notice to refer to its appearance .at the date of his letter. But these observa- 

 tions are of historical and scientific value ; and the author has not failed to press 

 for any further particulars or corroborative facts which it may be in Mr. Barker's 

 power to furnish. Several European astronomers, ignorant of Mr. Barker's observa- 

 tions, have conjectured that the star must have burst forth with astonishing sud- 

 denness. Mr. Schnadt, of Athens, a practised observer, thought it could not have 

 been so bright as a star of the fifth magnitude on the 12th of May, early in the 

 evening, or he must have perceived it ; and M. Courbisse, at La Eochelle, was 

 convinced it was invisible to the naked ej^e on the 11th; yet at this date it must 

 have shown, according to Mr. Barker's observations, as a star of the second mag- 

 nitude. This is by no means a solitary instance in proof of the little value which 

 attaches in many cases of a similar kind to merely negative evidence. In his own 

 astronomical practice the author had met with startling instances, and striking ones 



