630 



NATURE 



[October 25, 1900 



OUR ASTRONOMICAL COLUMN. 



I'HEMERIS FOR OBSERVATIONS OF EROS : — 

 . 1900. R.A. Decl. 



+ 52 36 sa'-o 



52 49 53*2 



53 2 9-2 

 53 13 38-2 

 53 24 i8-5 

 53 34 8-5 

 53 43 6-5 



+ 53 51 "-3 



Opposition of Eros. — M. Loewy has disiributed a fifth 

 circular containing additional information intended to secure 

 uniformity of observation among the many institutions which 

 have now commenced their work of determining the parallax of 

 Eros. It is advised that the positions relative to neighbouring 

 stars be measured in rectangular co-ordinates, and also that the 

 eleventh magnitude be adopted as the inferior limit of brightness 

 for the comparison stars. For those undertaking photographic 

 determinations, it is recommended — 



(i)That on each plate there be made two exposures of 

 different length, so that each star may be recorded by two 

 images some twenty seconds of arc apart in declination. This 

 procedure will fulfil the two functions of eliminating spurious 

 stars, and of enabling two series of measures to be made on star- 

 discs of very different diameters, so that the photographic 

 spreading effect may be allowed for to some extent. For in- 

 struments of the type employed for the international chart 

 (0-33 metre aperture), exposures of six and three minutes are 

 recommended. 



(2) On the plates especially for the planet's position, two ex- 

 posures should also be made, one while the guiding star is 

 accurately followed, the other keeping the planet on the cross 

 wires, or if this be too difficult on account of its faintness, 

 the guide star should be given a motion equal, and in the 

 contrary direction to that of the planet. The result of these 

 operations will be two images of Eros, one showing as a short 

 faint line, the other as a circular patch. This is now known to 

 be quite possible, as the planet has recently been photographed, 

 October 4 and 6, both at Paris and Algiers, in three minutes, 

 the magnitude being estimated at 10-5. Prof. Joly also states 

 that with the 15-inch reflector at Dublin, images were obtained 

 with exposures of six and two minutes. 



Another list of comparison stars is provided, and the ephemeris 

 extended to March 1901. The brightness of Eros is now slowly 

 increasing, being 9-81 magnitude on October 29, reaching its 

 maximum of 9-02 on December 18, and then decreasing to 10 48 

 in March at the close of the time of these special observations. 

 M. Loewy asks all collaborating in the enterprise to forward 

 regularly the successive progress made in the various sections. 



New Double Stars.— In the Aslronomische Nachrichten 

 (Bd. 153, No. 3668), Mr. R. G. Aitken gives the particulars 

 relating to 62 new double stars discovered by him with the 12-inch 

 equatorial of the Lick Observatory. This list is supplementary 

 to that previously published in Ast7-onoviische Nachrichten, No. 

 3635. Each star after discovery has been measured with the 

 36-inch telescope on at least one night ; 39 of the pairs are under 

 2" distance, 24 under i", and twelve under o"-5. The list has 

 been checked by comparison with Prof. Burnham's General 

 Catalogue of Double Stars. 



Astronomical Work at Daramona Observatory.— 

 We are in receipt of an interesting volume from Mr. W. E. 

 Wilson, containing reprints of the astronomical and physical 

 researches made at his observatory at Daramona," Westmeath, 

 since 1892. Mr. Wilson started in 1871 with a 12-inch equa- 

 torial, by Grubb, but did little more with this instrument than 

 lunar photography with wet plates and determinations of solar 

 radiation. In 1881, however, he built the present large observa- 

 tory attached to the house, and installed therein a new 24-inch 

 silver-on-glass mirror of 10 feet 6 inches focus. The old 12-inch 

 mounting proving too light for the extra load, it was replaced 

 in 1892 by one of the best pattern with Grubb driving clock 

 and electrical control. In 1889, an additional laboratory was 

 added for the physical investigations which have formed so large 

 a portion of the observer's programme.* 



The purely astronomical work with the 24-inch has practi- 

 cally been confined to the photography of star clusters and 



NO. 1617, VOL. 62] 



nebulae. Very beautiful reproductions in collotype of some of 

 these are included at the end of the volume. 



The astrophysical portions deal with experimental investiga- 

 tions on the heat of the sun, absorption of heat in the solar atmo- 

 spheres, thermal radiation of sun (both photosphere and spots) 

 and electrical measurement of starlight. 



HISTORICAL ASPECTS OF THE DISCOVERY 



OF THE CIRCULA TION OF THE BLOOD} 

 'T'HE discovery of the circulation of the blood by William 

 -*■ Harvey is commonly regarded among scientific discoveries as 

 eminent if not unique ; and this in the judgment not of 

 Englishmen only. My purpose to-day is to show that at any 

 rate it was made against enormous difficulties. 



To put this discovery in right perspective we must have some 

 vision of the history of philosophy, science and medicine. 

 Medicine, herein in contrast with Theology and Law, had its 

 sources almost wholly in the Greeks ; from them for good or 

 evil it took its first scheme of thought ; and in the schools of 

 Hippocrates and of Alexandria ir was based, more soundly, on 

 natural history and anatomy. The noble figure of Galen, the 

 first physiologist and the last of the great Greek physicians, 

 portrayed for us by Dr. Payne in the Harveian Oration of 1896, 

 stood eminent upon the brow of the abyss when, as if by some 

 convulsion of nature, Medicine was overwhelmed for fifteen cen- 

 turies. Galen practised the method of verification by experiment, 

 first introduced perhaps by Archimedes, but after him it was 

 lost till the time of Gilbert, Galileo and Harvey. 



In the growth of societies small civilisations have been sacri- 

 ficed to the formation of larger aggregates, whereby stable 

 equilibrium may be attained for the highest ends. Perhaps 

 because of her very freedom of thought Greece never became a 

 nation. Even the Roman peace, bought as it was at the cost of 

 learning and the arts, was but a mechanical peace. In the 

 wilder regions of the empire the bodies but not the wills, 

 of men were in subjugation, and even in Rome itself 

 the sanction of patriotism was failing. Under the Frankish 

 invasion the very traditions of learning and obedience 

 seemed to be broken up. Then Europe was saved by the in- 

 spiration of the Christian religion which, entering as a new 

 element into the ancient fabric of Roman empire, was now to 

 hold men's service in heart and soul as well as in body ; but to 

 this end no mere mystic or personal religion could suffice ; 

 clothing itself with the political and ritual pride, and even 

 with the mythology of the pagan empire, it inspired a new 

 adoration ; but it imposed upon men also a universal and 

 elaborated creed. In the third century philosophy was born 

 again in neo-platonism, the offspring of the coition of East and 

 West in Alexandria, where all religions and all philosophies met. 

 The world and the flesh were crucified that by the spirit man might 

 enter into God. Pure in its ethical mood, neo-platonism, says 

 Harnack, led surely to intellectual bankruptcy ; the irruption of 

 the barbarians was not altogether the cause of the eclipse of 

 natural knowledge. Yet even then, as again and again, the 

 genius of Aristotle came to save the human mind. Proclus, 

 ascetic as he was, was also versed in Aristotle ; he com- 

 pelled the Eastern mysteries into peripatetic categories, and 

 bequeathed a formal philosophy to the faith. Thus the first 

 Scholastic period was fashioned, and the objects and methods of 

 inquiry were determined for thirty generations. Rationalised 

 dogma lived upon dialectic, and conflicted with mysticism ; but 

 logic, dogma and mysticism alike disdained experience. The 

 Faith, then, was the first adversary of Copernicus, Galileo and 

 Harvey. 



It was the fortune of the Faith that, of all the treatises of 

 Plato, the Timseus, the most fantastic and least scientific, should 

 have survived to instruct the medieval world ; while those works 

 of Aristotle which might have made for natural knowledge fell 

 out of men's hands : moreover, the Categories and the " Inter- 

 pretation " made for more than Aristotelian nominalism, and 

 turned men's minds rather to rhetoric and dialectic than to 

 natural science. Thus Plato's chimrera of the human microcosm, 

 a reflection of his theory of the macrocosm, stood beside the 

 Faith as the second great adversary of physiology. 



The influence of authority, whereby Europe was to be 

 welded together, penetrated into all human ideas. As was 



1 Abstract of the Harveian Oration of igoo, delivered by Prof. Clifford 

 Allbutt, F.R.S. 



