INSTRUMENTS AND METHODS OF RESEARCH 1S7 



tung" (observation) and "Versuch" (experiment). The article 

 on " Beobachtung/' by the physicist Muncke, embraces 28 octavo pages. 

 He shows the distinction between " Beobachtungen " (observations) 

 and " Versuche " (experiments) to be that the former pertain to the 

 perceptions of phenomena presented to ns by nature in her unmodi- 

 fied course, whereas in the latter — in the experiments — we are seek- 

 ing to produce certain results or phenomena, more or less looked for, 

 in order either to verify a law already known or to disprove one sus- 

 pected of being wrong or even to discover a new one. Both classes 

 of experiences are necessary for a piece of investigation or research 

 work. 



Thus, we may behold either visually or in some other way certain 

 striking solar phenomena; these belong to the class of observations 

 which we ourselves are unable to modify in any manner whatsoever. 

 Continued observation may, however reveal a certain law which by 

 experiment in the laboratory, conducted along more or less definite 

 lines, we may seek to imitate in the hope of getting some clue to the 

 modus operandi of the observed phenomena. In this article on " Ob- 

 servations " the author treats in detail the various elements entering 

 into correct methods of investigation, condition of the observer and 

 of his senses, his being unbiased, character and errors of the instru- 

 ments, errors of results, methods of increasing accuracy, representa- 

 tions of observations by graphs and formulae, method of least squares, 

 etc. He points out the mistake sometimes made, that an established 

 formula satisfying the observed phenomenon within certain limits 

 represents an actual law of nature. 



The article "Versuch" (experiment) consists of 44 pages and is 

 contributed by the astronomer Littrow. He shows that the most rapid 

 development takes place in those sciences which afford the greatest 

 opportunity for experimentation, referring, e. g., to the slow and 

 painful progress of the astronomer as long as he had to confine him 

 self to mere celestial observations and the comparatively rapid 

 strides which occurred as soon as some of the observed phenomena 

 could be either imitated by, or be compared with, those derived by 

 laboratory experiment. The investigator, he says, must be abso- 

 lutely free from preconceptions and be careful, cautious and un- 

 biased in his interpretation of what his senses may reveal to him. 

 He illustrates how man, called jokingly "das TJrsachenthier " (the 

 animal ever bent on ascertaining the cause of things), proceeds in 

 ferreting out the why and wherefore of observed phenomena, and how 

 his methods of circumspection develop with the advance of Imowledge. 



Though man can not determine the " Endursachen,'^ or ultimate 

 causes of things, the field open to him to discover the laws governing 

 phenomena or, vice versa, classifying and enumerating those which 



