September 12, 1884.] 



SCIENCE. 



253 



lire, the evidence was very contradictory; but it may 

 be safe to add two other coincidences which seem to 

 be established: the number of small comets about 

 the sun seems to vary through a period about in 

 agreement with that of the sun-spots; and it has 

 been shown, particularly in photographs secured by 

 Professor Schuster himself, that the appearance of the 

 solar corona depends in some way on the same cycle. 



Professor Schuster was followed by Mr. W. Lant 

 Carpenter, who read a paper upon the same subject, 

 prepared by Prof. B. Stewart and himself. It con- 

 sisted, in the main, of a description of some very 

 elegant methods which they had made use of in dis- 

 cussing the temperature observations of Toronto and 

 Kew, for the purpose of detecting short periods com- 

 mon to solar and terrestrial phenomena. One of the 

 results of this investigation was to show, that, in 

 general, temperature phases make their appearance 

 at Toronto eight days before they appear at Kew; 

 while what might be called ' magnetic declination 

 range weather' travels from Toronto to Kew in 

 about one and six-tenths days. 



The subject was further discussed by several mem- 

 bers of the section, among whom was Eev. S. J. 

 Perry, who took a very conservative view of the mat- 

 ter, and declared that much research was demanded 

 before any thing really definite would be known. 



The sun, at least as to its spectrum, received further 

 attention from Professor Rowland and Rev. S. J. 

 Perry, — the former exciting great interest in the sec- 

 tion by an exhibition of several of his latest spectrum 

 photographs, and a discussion of the remarkable 

 advances in this direction which had followed, neces- 

 sarily, the use of his diffraction gratings. Mr. Perry's 

 paper was a discussion of observations on the spot 

 spectrum from D to B. 



Professor Carpmael described a new form of induc- 

 tion inclinometer which he had devised, which was 

 a modified form of Lloyd's instrument, a bifilar sus- 

 pension being substituted for an unifilar, and one or 

 two other changes made. The instrument had only 

 been in use a few weeks, but it promised to be of 

 considerable value. 



The Earl of Rosse described his method and ma- 

 chinery used for polishing specula, and with which 

 he had completed at Parsonstown a three-foot and a 

 six-foot speculum. He also described a device for 

 securing electrical control of an equatorial driving- 

 clock, which he had recently tried, and found to be 

 very satisfactory. It was essentially a ' see-saw ' 

 escapement, with a piece of soft iron on an extension 

 at one end, which moved between two electro-magnets, 

 being held firmly by each, during a certain portion of 

 the swing of the controlling pendulum. In this way, 

 he had secured accuracy and certainty of control, 

 even with crude apparatus. 



Mr. Perry, in speaking of the great importance of 

 accurate control of an equatorial, now that the spec- 

 troscope had come so to the front, said that it was 

 interesting to know that Mr. Huggins, in producing 

 some of the most perfect telescopic photographs that 

 had yet been made, had not especially felt the need 

 of a more perfect controlling device ; since Mrs. Hug- 



gins was constantly at his side to regulate the posi- 

 tion of the instrument, and that his splendid results 

 were largely due to her precision and patience. 



One of the most interesting and novel papers was 

 that of Professor Douglass Archibald, describing his 

 method of sending anemometers into the air by means 

 of kites, and thus studying the velocity of the air at 

 different heights. The carrying kite was seven feet 

 in length; and this was raised and afterward some- 

 what steadied by a smaller one about four feet long 

 attached to it. The anemometers were arranged at 

 different points along the line of the larger kite, so as 

 to record the velocity at various heights, in some 

 cases extending up as high as six hundred feet. 

 Although the experiments thus far made were only 

 preliminary in their character, some interesting re- 

 sults had been obtained. The velocity increased with 

 increased height, but at a diminishing rate. On 

 being questioned, Professor Archibald declared that 

 the most important thing about a kite was its tail. 

 In his kite the tail was made up of cones of canvas 

 arranged with their bases towards the wind, with the 

 cord running along their axes. They were placed at 

 a distance of three or four feet from each other, and 

 six were used. Sir William Thomson said that after 

 more than a century the kite was again being dedi- 

 cated to science, first on one continent, and now on 

 another. He was convinced that the device of Pro- 

 fessor Archibald was sure to prove to be of great 

 value in meteorological research. 



Professor Archibald made a brief reference to the 

 work already accomplished by a committee, of which 

 he was a member, known as the ' Krakatoa commit- 

 tee.' Their object was to determine, if possible, 

 whether the sun-glows or remarkable sunsets of the 

 past year could in any way be attributed to the 

 general diffusion of dust from the eruption of that 

 volcano. They had succeeded in collecting much 

 information, which had not yet been examined ; and 

 he could only say that nothing had yet appeared 

 which was inconsistent with the Krakatoa theory. 



Some further contributions to meteorology were 

 made in a paper by Professor James Thomson on 

 whirlwinds and waterspouts; in a note on internal 

 earth temperature by Mr. H. S. Poole, in which the 

 increase in temperature at Wolfville, N.S., was shown 

 to be in fair agreement w T ith other well-known deter- 

 minations; and in a paper by Dr. H. Muirhead on 

 the formation of mackerel sky. The latter was an 

 extension of the explanation suggested many years 

 ago by Sir William Thomson, by the introduction of 

 a third stratum of moving air. The effect of one 

 stratum moving over another, as Sir William Thom- 

 son had suggested, would be to produce 'waves' in 

 the air, which might result in long lines of cloud- 

 forms. A third stratum, moving in a direction at or 

 near a right angle to the first, would tend to break 

 these lines up into small patches, thus producing the 

 peculiar appearance known as the mackerel sky. 



Prof. Chandler Roberts interested the section great- 

 ly in presenting the results of some experiments 

 which he had carried out to show the diffusion of 

 metals;- the cases specially considered being the dif- 



