A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 299 



altre contrade d'ltalia nel 1 868 " (Fourth Memoir on Shooting-stars oh- 

 scrved in Piedmont and Italy, by Francesco Denza, Director of the Obser- 

 vatory of the Royal University of Moncalieri, near Turin) . — Several extracts 

 and references to the memoirs have been made in former Eeports, and 

 principally to the present memoir in this Eeport (Appendix III.) on the 

 August meteoric shower in 1868. 



2. " Le Metcore Cosmiche," Milano, E. Treves & Co., Biblioteca iitile, 1869, 

 by the same author, is a brief but lucid lecture, delivered to a popidar 

 audience at the Museum of Natural History and Philosophy in Florence, on 

 the subject of the recent discoveries incometic and meteoric astronomy. — The 

 aiithor, in common with Schiaparelli, regards comets, aerolites, and shooting- 

 stars as bodies of a common origin in the nebulous matter of the universe, 

 differing only from each other in the degree of concentration Tvrought in them 

 by the effects of universal gravitation and of time. The gaseous and self- 

 luminous character of the nucleus of Tempel's comet, observed by Huggins, 

 which is not referred to by Father Denza, differing so essentially from that of 

 aerolites, does not receive any very obvious or satisfactory explanation on 

 this hj'pothesis. 



3. •' Etudes geometriques sur les Etoiles filantes," par G. M. Goulier (in 

 8vo, pp. 154, with plates : Mctz, F. Blanc, 1868). — The principal object of the 

 work is an instructive manual intended to direct the observations of shooting- 

 stars projected by the recently instituted Meteor- Committee of the Imperial 

 Academy of Metz. The phenomena of visibihty, rate of apparition, appa- 

 rent position, and hourly variation of the radiant-point, and the calculations 

 of the real heights, velocities, and dates of the periodical rctiirns of shower- 

 meteors are discussed, with mathematical formulae intended to adapt the 

 careful observations of luminous meteors conveniently and with increased 

 accuracy to the development of the new cosmical theory of shooting-stars. 

 The same clear arrangement and demonstrations of all the fundamental pro- 

 positions of Professors Newton and Schiaparelli on the apparitions of shower- 

 meteors and their orbits are given in subsequent chapters of the work. The 

 sixth and last chapter contains a review of the conjectures to which the 

 cosmical theory of luminous meteors has given rise, and suggests some brief 

 considerations on the possible identity of shooting- stars and aerolites. 



4. " Zur Theorie der Sternschnuppen," von A. Erman (extracted from 

 Erman's 'Archives,' vol. xxv. part 3 : Berlin, 1867).- — A detailed account of 

 the attempts is given, which were made before the time of Schiaparelli, to 

 determine the form and dimensions of the August and November meteor- 

 orbits, — first, on the method employed by Erman, and adopted by other 

 observers of determining by direct observations the real velocities of the 

 meteors, relative to the earth ; and, secondly, in the manner adopted by 

 Professor Newton, of determining the periodic time of revolution by exam- 

 ining the dates of ancient star-shower records. The description of the first 

 of these two methods, adopted by astronomers fi'om the time of Ben- 

 zenberg and Brandos, occupies the principal and most extensive portion of 

 the narrative. The third, and last method, which led Schiaparelli to discover 

 the quasi-cometary character of the meteor-orbits by calculating the velo- 

 cities of shooting-stars from the laws of their annual and diurnal variations 

 of frequency, receives full exposition in the last few pages of the pamphlet. 



5. " Experiences synthetiques relatives aux Meteorites. Rapprochements 

 anxquelles ces experiences conduisent," par M. A. Daubre'e (in 8vo, pp. 68 : 

 Dunod, Paris, 1868). — The experiments of fusion and crystallization of 

 meteoiites and terrestrial rocks, and on the imitation of aerolites by the 



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