ON THE PROGRESS OF SCIENCE. XV 



stars ; nor could I find any objects in the lists of the ' Cycle' that were 

 not separated by the telescope and with ease. 



" Equally with regard to the range of visibility did the atmosphere 

 approve itself; for the very faintest star to the practised eye and pow- 

 erful telescope of the observer of the ' Cycle,' proved easy to even an 

 inexperienced person in the Pattinsou equatorial. 



" Directing them to planetary bodies, the fine division of Saturn's 

 ring a much contested matter came out unmistakeably, and revela- 

 tions of clouds appeared on Jupiter's surface which were eminently 

 similar in form, and as continually interesting in their changes as those 

 of the sea of lower clouds brought about Teneriife daily under our eyes 

 by the Isf.E. trade- wind." 



The expedition returned to England in October after an absence of 

 117 days, of which 36 were spent at sea, 18 in the lowlands of Tene- 

 riffe, 37 at the height of 8,870 feet, and 26 at the height of 10,900 feet. 

 The reduction of the observations is now in progress, and a detailed 

 report is being drawn up for presentation to the Admiralty. If the 

 expedition should be renew r ed another year for which the present 

 report gives every encouragement the experience of Prof. Smyth will 

 enable him to take fuller advantage of the time and instruments that 

 may be at his disposal. 



Astronomers are now eagerly on the look-out for the expected return 

 of the comet of 1556. The evidence of the identity of that comet 

 with the one Avhich appeared in 1264 is now generally admitted. 

 From the computation of the perturbations due to planetary attraction 

 between 1264 and the present time, it is believed that the course of the 

 comet has been accelerated, and therefore a speedy re-appearance is 

 probable. Mr. Hind published in the " Monthly Notices of the P.oyal 

 Astronomical Society," in 1847, an orbit, founded upon a rough chart 

 of its path, copied into various works from an original publication by 

 Paul Fabricius, attached to the court of Charles V. Subsequent inqui- 

 ries, through the aid of Prof. Littrow, the Director of the Imperial 

 Observatory at Vienna, led to the recovery of the original chart of 

 Fabricius, and brought to light a still more important treatise, by 

 Joachim Heller, astronomer, of Nuremberg, copies of which exist in 

 the ducal libraries of "Wolfenbuttel and Gotha. The observations of 

 Fabricius extend over less than a fortnight : whereas those of Heller 

 give the positions of the comet during an interval of fifty-three days. 

 The exact alterations in the orbit required by the calculations founded 

 on Heller's observations are not yet determined ; but the principal cor- 

 rection is a diminution of the comet's path to the ecliptic to the extent 

 of about one degree, which Mr. Hind views in connexion with the 

 acceleration of its return. 



At- a late meeting of the Royal Society, a communication was read 



