110 Rayleigtis Address to the British Association. 



the laborious accumulation of facts, it would soon come to a 

 standstill, crushed, as it were, under its own weight. The sug- 

 gestion of a new idea or the detection of a law, supersedes much 

 that had previously been a burden upon the memory, and, by 

 introducing order and coherence, facilitates the retention of the 

 remainder in an available form. Those who are acquainted with 

 the writings of the older electricians will understand my meaning 

 when I instance the discovery of Ohm's law as a step by which 

 the science was rendered easier to understand and to remember. 

 Two processes are thus at work side by side, the reception of new 

 material and the digestion and assimilation of the old ; and as 

 both are essential we may spare ourselves the discussion of their 

 relative importance. One remark, however, should be made. 

 The work which deserves, but I am afraid does not always receive, 

 the most credit, is that in which discovery and explanation go hand 

 in hand, in which not only are new facts presented, but their 

 relations to old ones is pointed out. 



In making ourselves acquainted with what has been done in 

 any subject, it is good policy to consult first the writers of highest 

 general reputation. Although in scientific matters we should aim 

 at independent judgment, and not rely too much upon authority, 

 it remains true that a good deal must often be taken upon trust. 

 Occasionally an observation is so simple and easily repeated, that 

 it scarcely matters from whom it proceeds ; but as a rule it can 

 hardly carry full weight when put forward by a novice whose care 

 and judgment there has been no opportunity of testing, and whose 

 irresponsibility may tempt him to " take shots," as it is called. 

 Those who have had experience in accurate work know how easy 

 it would be to save time and trouble by omitting precautions and 

 passing over discrepancies, and yet, even without dishonest inten- 

 tion, to convey the impression of conscientious attention to details. 

 Although the most careful and experienced cannot hope to escape 

 occasional mistakes, the effective value of this kind of work depends 

 much upon the reputation of the individual responsible for it. 



In estimating the present position and prospects of experimental 

 science, there is good ground for encouragement. The multiplica- 

 tion of laboratories gives to the younger generation opportunities 

 such as have never existed before, and which excite the envy of 

 those who have had to learn in middle life much that now forms 



