The health of Thayer had never been robust, and the long and unintermittent application to the work of gathering and weighing evidence had greatly taxed his brain. He became subject to severe headaches and after the appearance of the third volume he found it impossible to apply himself for even a short time to work upon the biography. In July, 1890, he wrote a letter to Sir George Grove which the latter forwarded to this writer. In it he tells in words of pathetic gratitude of the unexpected honors showered upon him at Bonn when at the invitation of the Beethoven-Haus Verein he attended the exhibition and festival given in Beethoven’s birthplace a short time before. Then he proceeds: “Of course the great question was on the lips of all: When will the fourth volume appear? I could only say: When the condition of my head allows it. No one could see or have from my general appearance the least suspicion that I was not in mental equal to my physical vigor. In fact, the extreme excitement of these three weeks took off for the time twenty years of my age and made me young again; but afterwards in Hamburg and in Berlin the reaction came. Spite of the delightful musical parties at Joachim’s, Hausmann’s, Mendelssohn’s ... my head broke down more and more, and since my return hither, July 3rd, has as yet shown small signs of recuperation. The extreme importance of working out my fourth volume is more than ever impressed upon my mind and weighs upon me like an incubus. But as yet it is still utterly impossible for me to really work. Of course I only live for that great purpose and do not despair. My general health is such that I think the brain must in time recover something of its vigor and power of labor. What astonishes me and almost creates envy is to see this wonderful power of labor as exemplified by you and my neighbor, Burton. But from boyhood I have had head troubles, and what I went through with for thirty years in supporting myself and working on Beethoven is not to be described and excites my wonder that I did not succumb. Well, I will not yet despair.” Thayer’s mind, active enough in some things, refused to occupy itself with the Beethoven material; it needed distraction, and to give it that he turned to literary work of another character. He wrote a book against the Baconian authorship of Shakespeare’s works; another on the Hebrews in Egypt and their Exodus (which Mr. E. S. Willcox, a friend of many years, published at his request in Peoria, Illinois). He also wrote essays and children’s tales. Such writing he could do and also attend to his consular duties; but an hour or two of thought devoted to Beethoven, as he said in a letter to the present writer, brought on a racking headache and unfitted him for labor of any kind.