559 



SCIENTIFIC SIDE-LIGHTS 



Progress 



vest in the future; and he has not lived 

 in vain who leaves behind him as his suc- 

 cessor a child better educated morally, in- 

 tellectually, and physically than himself. 

 HENRY Thoughts on Education (Scientific 

 Writings, vol. i, p. 327). (Sm. Inst., 1886.) 



2755. PROGRESS OF LIFE IN GEO- 

 LOGIC TIME Prolific Periods and Epochs. 

 Just as the growth of trees is promoted 

 or arrested by the vicissitudes of summer 

 and winter, so in the course of the geological 

 history there have been periods of pause 

 and acceleration in the work of advance- 

 ment. This is in accordance with the gen- 

 eral analogy of the operations of Nature, 

 and is in no way at variance with the doc- 

 trine of uniformity already referred to. Nor 

 has it anything in common with the un- 

 founded idea, at one time entertained, of 

 successive periods of entire destruction and 

 restoration of life. Prolific periods of this 

 kind appear in the marine invertebrates of 

 the early Cambrian, the plants and fishes 

 of the Devonian, the batrachians of the Car- 

 boniferous, the reptiles of the Trias, the 

 broad-leaved trees of the Cretaceous, and the 

 mammals of the early Tertiary. A remark- 

 able contrast is afforded by the later Ter- 

 tiary and modern time, in which, with the 

 exception of man himself, and perhaps a 

 very few other species, no new forms of 

 life have been introduced, while many old 

 forms have perished. DAWSON Facts and 

 Fancies in Modern Science, lect. 3, p. 124. 

 (A. B. P. S.) 



2756. PROGRESS OF SCIENCE Ad- 

 vance by Rejection of Ancient Dogmas Lan- 

 guage Still Preserves Old Forms. The dog- 

 mas of former ages survive now only in 

 the superstitions of the people and the 

 prejudices of the ignorant, or are perpetua- 

 ted in a few systems, which, conscious of 

 their weakness, shroud themselves in a veil 

 of mystery. We may also trace the same 

 primitive intuitions in languages exuberant 

 in figurative expressions; and a few of the 

 best chosen symbols engendered by the hap- 

 py inspiration of the earliest ages, having 

 by degrees lost their vagueness through a 

 better mode of interpretation, are still pre- 

 served among our scientific terms. rHuM- 

 BOLDT Cosmos, vol. i, int., p. 24. (H., 1897.) 



2757. 



A Rhythmic Move- 



ment Retardation the Prelude to Swifter 

 Advance. Newton's espousal of the emis- 

 sion theory [of light] is said to have re- 

 tarded scientific discovery. It might, how- 

 ever, be questioned whether, in the long run, 

 the errors of great men have not really their 

 effect in rendering intellectual progress 

 rhythmical, instead of permitting it to re- 

 main uniform, the " retardation " in each 

 case being the prelude to a more impetuous 

 advance. It is confusion and stagnation, 

 rather than error, that we ought to avoid. 

 Thus, tho the undulatory theory was held 

 back for a time, it gathered strength in the 



interval, and its development within the 

 last half century has been so rapid and tri- 

 umphant as to leave no rival in the field. 

 TYNDALL Lectures on Light, lect. 2, p. 80. 



(A., 1898.) 



2758. 



New Methods of 



Research. Comparing the methods now 

 available for astronomical inquiries with 

 those in use thirty years _ago, we are at 

 once struck with the fact that they have 

 multiplied. The telescope has been supple- 

 mented by the spectroscope and the photo- 

 graphic camera. Now this really involves 

 a whole world of change. It means that as- 

 tronomy has left the place where she dwelt 

 apart in rapt union with mathematics, in- 

 different to all things on earth save only 

 to those mechanical improvements which 

 should aid her to penetrate further into the 

 heavens, and has descended into the forum 

 of human knowledge, at once a suppliant 

 and a patron, alternately invoking help from 

 and promising it to each of the sciences, and 

 patiently w r aiting upon the advance of all. 

 The science of the heavenly bodies has, in a 

 word, become a branch of terrestrial physics, 

 or rather a higher kind of integration of 

 all their results. CLERKE History of As- 

 tronomy, pt: ii, ch. 13, p. 512. (BL, 1893.) 



2759. PROGRESS, SOCIAL Intellectual 

 Beliefs Direct Feelings Impel to Action 

 Steam and Steersman. It was not human 

 emotions and passions which discovered the 

 motion of the earth, or detected the evidence 

 of its antiquity; which exploded scholasti- 

 cism, and inaugurated the exploration of 

 Nature; which invented printing, paper, and 

 the mariner's compass. Yet the Reforma- 

 tion, the English and French Revolutions, 

 and still greater moral and social changes 

 yet to come, are direct consequences of these 

 and similar discoveries. Even alchemy and 

 astrology were not believed because people 

 thirsted for gold and were anxious to pry 

 into the future, for these desires are as 

 strong now as they were then; but because 

 alchemy and astrology were conceptions nat- 

 ural to a particular stage in the growth of 

 human knowledge, and consequently de- 

 termined during that stage the particular 

 means whereby the passions which always 

 exist sought their gratification. To say that 

 men's intellectual beliefs do not determine 

 their conduct is like saying that the ship 

 is moved by the steam and not by the steers- 

 man. The steam, indeed, is the motive 

 power; the steersman, left to himself, could 

 not advance the vessel a single inch, yet it 

 is the steersman's will and the steersman's 

 knowledge which decide in what direction 

 it shall move and whither it shall go. 

 MILL Positive Philosophy of Auguste Comte, 

 p. 96. (H. H. & Co., 1887.) 



2760. PROGRESS, UNCONSCIOUS 



The Greatest Movements Least Perceptible 

 to Those Borne Onward ~by Them. If we 

 ride in a well-appointed carriage with good 



