466 



NATURE 



\SepL 15, 1881 



of the solar photosphere — or in other word?, the total area 

 occupied liy the suns[>ots — was no less than live thousand two 

 hundred luillion square mile-, or about twenty-.^even times that 

 of the superficies of the earth ! So again in August and Sep- 

 tember, 1870, immense groups, occupying from four to tive 

 thousand million square miles, were observed to make t\\o con- 

 secutive revoluiions, and on the latter of which two occasions a 

 beautifully enlarged photograph of the sun, twenty-four inches 

 in diameter, was made by Mr. Titterton of Ely, under the 

 auspices of the late Canon Selwyn, and exhibited to Section 

 A. On all these occasions great magnetic disturbances, amount- 

 ing often to absolute magnetic storms, were unequivocally 

 manifested; and in fact out of twenty-four comparisons insti- 

 tuted, the following is the summary of results, as showing the 

 coincidence of extensive solar sctivity and synchronous magnetic 

 disturbances : — 



Intensely 51 



Very decidedly 3 



Decidedly 9 



Moderately 3 | 



Negatively (no sjots, no storms) ... l] 



Questionable I ] 



Contradictory 2 j 



= 21 affirmatively 



3 contradictory 



24 



Thus then, from the data collected, it would certainly 

 appear that marked periods of solar activity are wont to 

 coincide with marked periods of terrestrial niagnet'C disturb 

 ances ; but yet from a careful comparison of the days and 

 hours of the magnetic records appealed to, it also appeared that 

 the disturbances were rcanifested in a variety of ways, not only 

 iiS re-arded the extent of the magnetic excursions of the needle, 

 ihe rapidity of the oscillations, or the persistency of the more 

 moderate disturbances, but also they viere found to follow at 

 consideiably different intervals of time after ihe commencement 

 of the observed solar outbursts. With respect, lastly, to reac- 

 tionary influences, Mr. Howlett stated, on the authority of Mr. 

 Whip] le, the director of the Kew Observatory, that on the 

 occa i n of the perihelion pas- age of comet b 1881, on the i6th 

 day of June last, the terrestrial magnetic curves we: e unu: ually 



. quiescent. 



On Arlificial Flij^ht, by Fred. W. Brearey. — The author ]iro- 

 ceeded to argue that the %veight Cif the bird plays an active part in 

 its flight, and that this result arise- frr m tie action of that portion 



-of the pectoral muscle \i hich depres es the wing. So great is 

 the tensii n of this muscle that it is highly probable that, in the 

 case of those lung-w inged and heavy birds w hith are able to fly 

 without apparently moving a feather, the vings are lept ex- 

 tended aga nst the resistance of the air underneath without any 

 voluntary efl'ort of the bird. Its weight pressing upon the air 

 causes this muscle to expand in raising the wing, and aids in the 

 effect of the do\\ nward stroke by its contraction. The author 

 exhibited a model with wings 4 feet from tip to tip and 3 fett 

 2 inches from head to tail. The wings are moved by M. 

 Penaua's plan of strands of india-rubber previously put into a 

 -State of tension, which in unwinding create a flapping of the 

 wings. By an india-rubber coid attached to the under part of 

 the wing and passing under the shaft to which the mechanism is 

 attached an equdibnum betw een the two forces is attained ; that 

 is to say, the india-rubber strands are wound up to that extent 

 that the wings in rising stretch the india-rubber cord — or, as the 

 author calls it, the pectoral cord — until one foi'ce neutralises the 

 other; so thc.t, held in the hand, there is no action. When 

 liberated, and committed to the jjcssure of the air, the w eight 

 of the model causes the wings to be elevated, and iherelora 

 stretches the pectoral cord, which in its contraction assists the 

 power derived from the twisted rubber in depressing the wings 

 against the weight tf the model. During this action the flight 

 is well .sustained for 40 feet or more. The author states that an 

 apparatus of the nature of a longitudinal parachute w as liberated 

 fi'om a balloon which rose from Woolwich anenal, and it tia- 

 velled back, by the aid of gravity alone, to the ar enal, a 

 di-tance of half a mile, from thi^ he argued that if the fabric 

 can be manipulated ; o that piropul ion al-o can be imparted to 

 it, then some encouraging rc: ults W( uld Le likely to follow. He 

 showed a model of large size upon this principle, and how, by 

 the action of the wing-arms, a wave is transmittted from head to 

 tail along a loose ; urface in ; hape like a kite. This loose su;- 

 ace requires a fall before it can be inflated liy the air under- 



neath ; the wave-motion of the wings is then found adequate to 

 its propulsion. 



On the Arrcstation of Infzisor:al Life, by Prof. Tyndall. — 

 Three years ago I brought wiih me to the Alps a number of 

 flasks charged with animal aird veget: ble infusions. The flasks 

 had been boiled from three to five minutes in London, and her- 

 met cally sealed during ebullition. Two years ago I had sent to 

 me to Switzei-land a batuh of similar flasks containing other 

 infusions. On my arrival htre this year 120 of these flasks lay 

 upon the shelves in my Utile library. Though eminently 

 putrescible, the animal and vegetable juices had remained as 

 sweet and clear as when they were pi'epored in London. Still an 

 expert taking up one of the flasks containing an infusion of beef 

 or mutton would infallibly pmiounce it to be charged with 

 organisms. He w. uld find it more or less turbid throughout, 

 with massive flocculi moving heavily in the liquid. Exposure of 

 the flask for a minute or two to lukewarm water would cause both 

 turbidity and fl cculi to disappear, and render the hifusion as 

 clear as the purest distilled water. The turl idily and flocculi 

 are sim| ly due to the coagulation of the liquid to a jelly. This 

 fact is some guarantee for the strength of the infusions. I took 

 advantage of the clear weather this year to investigate the action 

 of solar light on the development ot life in these infusions, being 

 prompted thereto by the intere. t ng observations brought before 

 the Koyal Society by Dr. Downs and Mr. Blunt in 1877. The 

 sealed ends of the flasks being broken off, they were infected in 

 part by the water of an adjacent brook, and in part by an infusion 

 well charged with organisms. Hung up in rows upon a board, 

 half the flasks of each row were securely shaded from the sun- 

 the other half being exposed to the light. In some ca-es, uore, 

 over, flasks were ] laced in a darkened room within the house, 

 while their companions were exposed in the sunshine outside. 

 The clear result of these experiments, of which a considerable 

 number were made, is that by some constituent or constituents 

 of he solar radiation an influence is exercised inimicsl to the 

 development of the lowest infusoria. Tw entyft ur hours usually 

 sufficed to cause the shaded flasks to pass from clearness to tur- 

 bidity, while three this time left the exposed ones without 

 sensille damage to their transpiarency. This result is not due 

 to mere differences of temperature between the infusions. On 

 n any occasions the temperature of the exposed flasks was far 

 more favourable to the developu ent of life than that of the 

 shaded ones. The energy which in the cases here referred to 

 pirevented ^utrefactiol^ was energy in the radiant form. In no 

 case have I found the flasks sterilised by insolation, for on re- 

 moving the exposed ones from the open air to a warm kitchen 

 they infallibly chcnged from tlearness to turbidity. Four and 

 tv\ en'y hours w ere in most cases sufficient to produce this change. 

 Life i', therefore, pi\ vented from developing itself in the in- 

 fusions as kng as they are exposed to the solar light, and the 

 paralysis thus produced enables them to jass thrcugh the night- 

 t'me wuhout alteration. It is, however, a suspension, not a 

 destruction, of the germinal jower, for, as before stated, when 

 placed in a warm room life was invariably c'eveloped. Had I 

 had the requisite materials 1 should hke to have determined by 

 means of coloured media or otherwise the particular constituents 

 of the solar rcdiation which are concerned in this result. The 

 rays, moreover, which thus interfere with life must be absorbed 

 by the liquid or by its germinal matter. It would therefore be 

 interesting to ascertain whether, after transmission through a 

 layer of any infusion, the radiation still possessed the power of 

 arresting the development of life in the same infusir n. It would 

 also be interesting to examine how far iusolatii n u ay be em- 

 ployed in the preseivation of meat from putrefaction. I would 

 not be understood to say that it is impossible to sterilise an 

 infu'ion by insolation, but merely to indicate that I have thus far 

 noticed no case of the 1 ind. 



The Szitt-Sfot Paioa and Planclary Tides in the Solar Atmo- 

 sphere, 1 y F. B. Er'monds-. — The author said that tl e influence of 

 the planet may be localised on a surface or stratumef small thick- 

 ness, so that the disturbing force wculd vary as the square of the 

 distance of the plai.et. Under this supposititn the predomin- 

 ance of Jupiter seemed to shut out out the idea ihat;un-spct 

 maxima ai d minima could depend simply on the oppc siiion and 

 coiijunction of the planets. The consequence of such a suppo- 

 sition was not to be lost sight of, 1 ut maybe taken together 

 with the more general supposition that the attractive force is 

 exercised en a gasetus CLvelope, of which the altitude is not 

 in-ignificant. Again, the mass of the sun is rcted on by the 

 planets, and such jarts as are fluid, whether in ike liquid or 



