i 9 6 PETER GUTHRIE TAIT 



workshop of his thoughts and to reveal the way in which he looks at things, to 

 disentangle the guiding threads which have helped him in his bold intellectual 

 combinations to master and coordinate the intractable and tangled material, we can 

 but feel towards him the liveliest gratitude. For this work which would indeed 

 overstrain the powers of a single much occupied man, he has found in P. G. Tait, 

 Professor of Natural Philosophy in Edinburgh, a highly fit and gifted collaborator. 

 Only perhaps by such a happy union could the task as a whole have been completed." 



Helmholtz also speaks of the difficulty of finding German equivalents for 

 some of the new scientific terms invented by Thomson and Tait. That 

 verbal difficulties other than scientific troubled the minds of the German 

 translators is clear from the following letter from Tait to Helmholtz : 



17, DRUMMOND PLACE, EDIN. 



20/5/71. 

 Dear Professor Helmholtz, 



I have postponed my answer to your letter till I could catch Thomson, 

 so that the answer to your queries should come from him as well as from me. 

 Now that he has got a yacht he goes off for three weeks at a time ; and is now 

 on his way to Lisbon, and perhaps Gibraltar. However, he quite agrees with the 

 following answers. 



1. To "scull a boat" has two meanings 1 . In a sea-boat it means to work a 

 single oar at the stern like the tail of a fish. In a light racing boat on a river or 

 lake it means to work two oars in the rowlocks, one with either hand. This is 

 what we mean in the text. Thomson won the "sculls" in this sense when he was 

 a student in Cambridge. 



2. To "run up on the wind" means to turn the ship's head to the wind. 



3. To "carry a weather helm" means to put the tiller (Helmholtz?) to wind- 

 ward so that the rudder goes to the other side, tending to turn the ship's head from 

 the wind, providing she is moving fast enough to make the rudder act. 



As to your proposed changes on the new matter, I have no doubt whatever 

 that they will be improvements, and we have reason to rejoice that you are kind 

 enough to make them. 



Thomson desires me to say that, while we all regret you cannot come to the 

 B. A. Meeting, he will not forego your company on a cruise if it is possible to get 

 hold of you, and will make arrangements to start at any time that may suit you, 

 from August to November inclusive. But the best plan would be for you to try 

 to get to Edinburgh in time for the last day or two of the Meeting, which lasts 

 a week usually. This year we hold in Edinburgh the Centenary of Sir Walter Scott 

 just at the end of the Association Meeting ; and it is probable that, if you care at 

 all about his writings, you would be interested in seeing the collection of things 

 connected with him which will be exhibited then. If Sir William be not ready to 

 start, you might come with me to St Andrews, where my wife will be delighted 



1 The reference is to 336 in the first edition, considerably extended in 325 in the 

 second edition. 



