672 



NATURE 



[July 29, 1920 



leag^ues for the able way in which they have 

 dealt with their onerous task. 



Mr. Howard, Imperial economic botanist to the 

 Government of India, directed attention recently, 

 at the Royal Society of Arts, to the future of 

 economic botany in India and to the many com- 

 plex problems awaiting- solution : after asking what 

 is the best method of getting such work done — 

 whether we should rely on organisation or trust 

 to the individual — he expressed the opinion that 

 individual action is to be preferred. But surely 

 the competent individual should be able to influ- 

 ence a receptive though unimaginative multitude. 

 Increase in knowledge is of little value if it do 

 not give us an increase of power to use our know- 

 ledge — we know that it does. During the war, 

 much organised team work was accomplished by 

 scientifically trained workers under the influence 

 of a few guiding minds. The men who are doing- 

 research work in the various schools are for the 

 most part unconscious members of a service act- 

 ing under the inspiration of a few leaders : there 

 is no reason why the system should not be carried 

 from academic life into the public service. We 

 are alive to the faults by which a public system is 

 likely to be affected and should be able to guard 

 against them. Henry E. Armstrong. 



Tycho Brahe. 



Tychonis Brahe Dani Opera Omnia. Edidit 

 I. L. E. Dreyer. Tomus vi. Pp. v-f375. 

 (Hauniae : Libraria Gyldendaliana, 1919.) Price 

 19 kr. 



MR. HAGEMANN, who is bearing the ex- 

 pense, and Dr. Dreyer, who has under- 

 taken the labour of editing the works of Tycho 

 Brahe, are alike to be congratulated on the ap- 

 pearance of this elegant edition of the first 

 book — the only one ever published — of the " Epis- 

 tolae AstronomicEe." The frontispiece consists of 

 a handsome portrait of Tycho Brahe, dated 1586, 

 reproduced from the first edition, which appeared 

 in 1596. Here the portrait is enclosed in an arch 

 ornamented with sixteen coats-of-arms, either, we 

 may conjecture, his sixteen quarterings, or at 

 least the arms of his own and fifteen kindred 

 families. The English reader will note with 

 special interest the arms of Rosenkrans and Gul- 

 densteren, and we have not far to seek for bearers 

 of those arms. In Dr. Dreyer's "Tycho Brahe" 

 (1890) Jorgen Rosenkrands is frequently mentioned 

 as a patron of Tycho. He was Governor of Jut- 

 land, and in 1588 was made one of the Council 

 of Regency for the young King Christian IV. of 

 NO. 2648, VOL. 105] 



Denmark. Axel Guldenstern appears in two 

 letters in the present volume dated 1592, where he 

 is described as a kinsman of Tycho and Governor 

 of Norway. 



The letters contained in the present volume 

 range in date from 1585 to 1595. They comprise 

 the correspondence of Tycho Brahe with Wilhelm, 

 Landgrave of Hesse-Cassel, his son and successor 

 Moritz, and his " mathematicus " Rothmann. The 

 letters are partly in Latin and partly in German, 

 but the German letters are always accompanied 

 by a Latin translation. Their contents are well 

 exploited in Dr. Dreyer's "Tycho Brahe," men- 

 tioned above, and in his " History of the Planetary 

 Systems " (1906). Perhaps the most generally 

 interesting part of the present collection is the 

 description of Tycho's observatory at Hveen and 

 of his instruments, which occupies pp. 250-95 of 

 this volume. Tycho's attitude to astronomy 

 and astronomers is well illustrated by the 

 selection of eight, whose portraits adorned the 

 crypt of his observatory — Timocharis, Hipparchus, 

 Ptolemy, Albategnius, Alfonso, Copernicus, 

 Tycho Brahe, and Tychonides, with the pithy 

 distichs in which Tycho sums up the importance 

 of each (pp. 274, 275). 



The correspondence with Rothmann will remain 

 famous for the clearness with which Rothmann 

 grasped the implications of the Copernican system, 

 and maintained them against Tycho's futile objec- 

 tions, which, to men brought up to believe in a 

 stationary earth, appeared so cogent. It is some- 

 what pathetic that this record of the ancient con- 

 troversy should have appeared only a few weeks 

 before the triumphant vindication of a new theory 

 which renders the difference between Copernicus 

 and Tycho meaningless. 



Tycho was the first of modern astronomers to 

 make more than occasional observations, and it 

 was therefore natural that the work of the ancient 

 observers, particularly Timocharis, Hipparchus, 

 and Ptolemy, should possess a living interest for 

 him and his correspondents instead of having, as 

 to nearly all modern astronomers, a purely anti- 

 quarian importance. Rothmann (p. 115) made one 

 unhappy suggestion about Ptolemy which can 

 scarcely have l^een intended for publication. Cer- 

 tainly the author can never have dreamed of the 

 way in which it was to be extended. The sug- 

 gestion is that the places of the fixed stars in 

 Ptolemy were not observed by him, but merely 

 transcribed from Hipparchus. Rothmann shows, 

 quite correctly, that the latitude which Ptolemy 

 professes to have observed for Regulus is incon- 

 sistent with the longitude and declination which 

 he also professes to have observed ; his own 

 ' observations, he says, are not inconsistent with 



