306 PHEIS'OMENA MANIFESTED IN TELEGRAPHIC LINES, ETC 



such positions that every ten years Jnpiter is either in conjunction or 

 in opposition with Saturn. Other relations seem to exist between the 

 solar spots and the positions of the planets. Messrs. DeLaEue, Stewart, 

 and Loewy, in a series of essays, which they published together from 

 1845 to 1848, concerning the physics of the sun, have shown that the 

 spots of this luminary (irrespective of their number) increase in size 

 when, by means of the solar rotation, they are carried farthest from the 

 l>{ace which Venus occupies in space, and that they diminish in size 

 when they aproach that i>lanet. Mars also contributes to the increase and 

 decrease of the size of the solar s^iots in the same way that Yenus does, 

 but his influence is less powerful than that of Venus, perhaps on ac- 

 count of his greater distance from the sun. Mercury seems to possess 

 somewhat of a similar influence, which, however, shows itself less dis- 

 tinctly on account of the rapidity with which he moves round the sun. 

 The position as well as the size of the solar spots depends on the place 

 occupied by the planets in space. When Jupiter and Venus, in their 

 orbital motions, cross the plane of the solar equator, then the spots 

 appear nearer the same equator : and, on the contrary, when these two 

 l)lanets occupy positions distant from the sun's equator, then these spots 

 also appear ferthest from the same equator. 



From some observations made on the occasion of the solar ecli]ise, 

 December 22, 1870, Professor Serpieri concludes that the protuberances 

 Avhich emerge from the sun during the eclipses are directed toward the 

 planets. In fact, he observed one protuberance bending toward Saturn. 

 Serpieri's conclusions seem confirmed by other observations made by 

 Professor Tacchini, who, on the 27th May, 1871, saw, while the sun was 

 shining, one of those protuberances, which seemed directed toward a 

 group of planets. But if the number, the position, and the size of the 

 solar spots depend on the positions of the planets, terrestrial magnetism 

 must be dependent on the same ; for it is established, with considerable 

 certainty, that the phenomena of the variations and perturbations of 

 all the magnetic elements are also connected with the solar spots. Con- 

 sequently, (to resume the subject which more especially concerns us,) 

 the auroras also may somewhat depend on the relative positions of the 

 planets, and therefore they are subject to periodicity, and also advance 

 from east to west in the way and for reasons already mentioned. 



[The remainder of the paper of Professor Donati is occupied with a 

 defense of his claim to the foregoing hypothesis, which, being of no in- 

 terest to the readers of this report, is omitted. It is proper, however, to 

 remark that, in this translation, the expression electrical currents has 

 been substituted for the phrase magnetic currents, used by the author. 

 The reasons for this change are, because this is the term used by Sir 

 John Herschel in the quotation from his astronomy by Professor Donati, 

 and furthermore because there is, strictly speaking, nothing in the phe- 

 nomenon of magnetism to which we can apply the term current, or a trans- 

 ference of magnetism from one body to another, as is the case in the phe- 



