XVIII 'J OBSERVATION. 



403 



1 the f forces { the P^lem, and the true course of 

 i nature might still be rendered apparent. But the 

 feelings of an observer are usually too indeterminate, so 

 hat when there is reason to suspect considerable bias re- 

 jection is the only safe course. As regards facts casually 

 registered m past times, the capacity and impartiality of 

 the observer are so little known that we should spare no 

 s to replace these statements by a new appeal to 

 nature. An indiscriminate medley of truth and absurdity 

 such as Francis Bacon coUected in his Mural History & 

 wholly unsuited to the purposes of science. But of course 

 when records relate to past events like eclipses, con! 

 June ions, meteoric phenomena, earthquakes, volcanic 

 eruptions, changes of sea margins, the existence of now 

 act animals, the migrations of tribes, remarkable 

 customs, &c., we must make use of statements however 

 unsatisfactory, and must endeavour to verifiy them b y the 

 comparison of independent records or traditions 



When extensive series of observations have to be made 

 as m astronomical, meteorological, or magnetical observa-' 

 tones, trigonometrical surveys, and extensive chemical or 

 physical researches, it is an advantage that the numerical 

 ina d be executed by assistants who ^not interested 

 ,. .1 L P aP I UnaWare f ' the ex P ected resul <*- The 



m ^even 



e desirable that those who perform the purely routine 

 work of measurement and computation should be un! 

 acquainted with the principles of the subject. The 

 table of logarithms of the French Revolutionary G 

 inent was worked out by a staff of sixty 



skilern f the direc ^n of 



found C ffJ yet their cal ^lations were usually 

 found more correct than those of persons more deeply 

 versed in mathematics.* In the Indian Ordnance Survey 

 the actual measurers were selected so that they should 

 SklU t0 Msi fy their results without 



bou th P h aSSiVe ^ sm ' ation a nd experimentation must 

 however, be generally conducted by persons who know for 



1 Babbage, Economy of Manufactures, p. 194. 



D V 2 



