PROFESSOR AT HEIDELBERG 207 



my while to work out my own solution for the press. The 

 principle of reflection from a spherical surface, by which 

 a straight edge can be converted into a circular one, was 

 also discovered (as he supposed) by another and very capable 

 young mathematician, Lipschitz, but happily we came on it in 

 time in your previous work. Unfortunately I have already 

 published it in a short Note in the Transactions of our own 

 Scientific Society, for which I must beg your pardon ; but in 

 its fuller exposition by Lipschitz, the priority will be given 

 to you/ 



Thomson at once gave him full information upon these 

 mathemical points. 



Meantime, the great work on Acoustics was nearing its 

 completion; on April 29, 1862, Helmholtz writes to Bonders 

 (after telling him that a son had been born on March 3, who 

 received the names of Robert Julius, and whose life nearly cost 

 that of his mother) : 



' As to my work on acoustics, A Physiological Basis for the 

 Theory of Music, the blocks are made, the text is being set up, 

 and two-thirds of the manuscript have been sent off: there is 

 a good deal still to alter and patch up in the last third, but the 

 most important parts are already written. I shall be thankful 

 when I have finished the last words of this long-winded under- 

 taking, for I have been working on it for seven years, which 

 certainly won't be seen from the size of the book. And then 

 very likely the philosophers and musicians will regard it as 

 trespassing on their domain, while there are not many musical 

 people like yourself, for instance, among the physicists and 

 physiologists. You will be my most intelligent critic, and 

 I shall be very curious to hear whether my bold attempt to 

 bring scientific methods into aesthetics will meet with your 

 approval.' 



The busiest and most productive period of Helmholtz's life 

 in Heidelberg opened with the year 1862. His Theory of the 

 Sensations of Tone and Physiological Optics were both near 

 their completion ; his epistemological views were shaping 

 themselves into a consistent system of philosophy; he was 

 incessantly occupied with problems in hydrodynamics and 

 electrodynamics, and his thoughts were already turning to the 

 investigations of the axioms of geometry, which in a few 



