I ought to have said before that the book which I have just finished is called "Climatic Changes: Their Solar and Geological Causes." In it I have a cosmic theory of climatic changes which has a certain resemblance to yours, although in its main essence it is quite different. I had a queer experience in writing this book. A year ago last March it was my turn to speak before our university Geological Club. I told the professor that I had nothing new to say as I had not been working on geology for sometime; however, I could revamp some of my old ideas. I sat down to do so and to my surprise discovered that during the three or four years since I wrote my last article on climatic changes my ideas had progressed and crystallized to a surprising extent. In fact I found that I had what I had been looking for, a full fledged and, as it seemed to me, consistent hypothesis of climatic changes. You know the kind of click that goes through one's brain when all his ideas about a subject suddenly fall into place. It is one of the most delightful sensations.

Having thought the thing through I felt that I must put it down. I meant to write an article of four or five thousand words in the course of a week. The article grew and grew for two months. Then I put it aside to finish a book on Europe which I had been working on. Last fall in October I took it up again to polish it off and send it to some journal for publication. The moment I laid hands on it it began to grow once more. So I thought I would make a small book of it. It at once grew to a large book and that is what it is. I thought that I had finished it last February. One chapter, however, did not suit me, so ever since then I have spent most of my time and a very considerable bit of my money in working out statistics for that one chapter. That one chapter deals with the electrical relations between the earth and the sun. Now at last the book is finished and the manuscript will go to the publisher in a day or two.

I am off now to Milton, Mass., for the summer. There I must devote myself to writing a text book, for I find it necessary to earn money in order to balance up what I pay out for help in investigation.

With cordial regards,

Yours sincerely,

October 4, 1921.

Prof. Griffith Taylor,
University of Sydney,
Sydney, Australia.

My dear Taylor:

Thank you for the reprint of your article in the Geographical Review. It came during the summer and I have only just seen it. You had not yet received my long letter. I hope very much that I shall hear from you again in regard to the book I hope you are writing.

I spent my summer writing a book along quite different lines from my main work--a volume on business geography. It is well along toward completion and I hope to have it published sometime next winter.

With cordial regards, I am

Yours truly,

October 4, 1921.

My dear Taylor:

Thank you for your reprint of your article in the Geogrpphical