HIS PHYSICAL INTUITION 95 



Art. 577 



Not while the coil in spinning sleeps 



On her smooth axle swift and steady, 

 But when against the stops she sweeps, 



To watch the light spot then be ready, 

 That you may learn from its deflexion 

 The electric current's true direction. 



It may be that it does not move, 



Or moves, but for some other reason, 

 Then let it be your boast to prove 



(Though some may think it out of season 

 And worthy of a fossil Druid) 

 That there is no electric fluid. 



There is no evidence that Tait ever began on the line of work here 

 indicated. 



Taking a general view of Tait's experimental work we find it characterised 

 by a true physical insight into the essential nature of each problem. Super- 

 fine accuracy was never his aim ; and perhaps from this point of view some 

 of his investigations lack finish. His methods were in many cases rough 

 and ready, but they were always under complete mathematical control. 

 Having laid down the broad lines of attack on any question he put together 

 his apparatus with little apparent attention to detail ; but his intuitions generally 

 led him right. In many cases the first rough arrangement was committed to 

 the care of two of his "veteran" students, in whose hands the final form of 

 apparatus gradually evolved itself as difficulty after difficulty was surmounted. 

 In this way the resourcefulness of the master and the enthusiasm and 

 patient skill of the disciples worked together towards the perfected end. In 

 his published accounts Tait never failed to give full credit to those who 

 helped him in carrying his ideas to fruition. 



The most laborious experiments undertaken by Tait were those on the 

 conduction of heat in bars, on the errors of the " Challenger " thermometers, 

 on the compression of liquids and on the laws of impact. In all of these 

 Thomas Lindsay was his righthand man ; and the successive bands of students 

 who helped in the work consisted, in a sense, of picked men, for in those 

 days only real enthusiasts ever thought of continuing their laboratory work 

 so as to rank as "veterans." Already I have incidentally named a few of the 



