SECTION 10. EXPERIMENT AND USE OF INSTRUMENTS. 83 



impossible to believe which incidentally and pointedly proves 

 the absence of an accepted methodology that this should not 

 have been accomplished already. Once numerous observational 

 experiments of this character have been completed, and the 

 general mentality of the species has been ascertained, the 

 situation could be complicated by subjecting the animals to 

 artificial tests. 



Instruments are not indispensable to experiment, though little 

 can be achieved without them. Galileo, in his experiments 

 from the leaning tower of Pisa, employed no specially devised 

 instruments, and many experiments in agriculture and legis- 

 lation, and in other departments of knowledge, are executed 

 without their assistance. Not a few of Darwin's experiments 

 possessed a homely character, and Galton's famous enquiry 

 relating to mental imagery was markedly simple and non- 

 instrumental. 1 On the other hand, microscopes, telescopes, 

 spectroscopes, and a multitude of other aids, are employed in 

 observation, since instruments multiply the power and the 

 delicacy of the senses almost an infinite number of times. 2 

 We may, consequently, distinguish between instrumental and 

 non-instrumental observation and experiment. In observation 

 neither the object observed nor its environment would be de- 

 signedly altered ; in experiment one or both would be affected. 

 Instruments, again, may be divided into scientific and non- 

 scientific ones. Scientific instruments are such as are carefully 

 calculated to attain the end aimed at in an easy, an exact, 

 and a measurable manner. Non-scientific instruments more or 

 less lack these qualifications. Determining the weight of a sub- 

 stance by weighing it respectively in the hands and on a tested 

 and sensitive pair of scales, may fix the distinction between 

 the two. It is somewhat difficult to define use and non-use 

 of instruments. For practical purposes, however, the above 

 definition of instrument is passable, especially when it is a 

 question of scientific instruments. Similarly the meaning of 

 change in object and environment is only subject to a minimum 

 of misconception, because our presence, for instance, may be 

 readily discounted: our weight; shadow thrown; the air altered 



1 According to the Encycl. Brit, (llth ed.), so distinguished a modern 

 physicist as Lord Rayleigh did not despise simple experiments: "The ex- 

 perimental investigations are carried out with plain and usually home-made 

 apparatus, the accessories being crude and rough, but the essentials thought- 

 fully designed, so as to compass in the simplest and most perfect manner 

 the special end in view." 



2 Interesting chapters on the use of instruments will be found in Jevons 

 and Venn. We shall cite a certain modern instrumental mode of procedure 

 because of its important bearings in palaeontological enquiry. "By means 

 of spreading mucilage and tissue paper over delicate bones that crumble on 

 exposure to the air, and the wrapping of fossils in plaster casts for trans- 

 portation, it has been made possible to uncover and preserve many struc- 

 tures which, with a rougher method of handling, would have been lost to 

 science." (W. A. Locy, op. cit., p. 340.) 



