xxxiii] LITERARY WORK, ETC, 1887-1905 231 



The lecture which I gave at Davos on the science of the 

 nineteenth century (a subject suggested by Dr. Lunn) led me 

 to think that an instructive and popular book might be made 

 of the subject, as I found there were so many interesting 

 points I could not treat adequately or even refer to in a 

 lecture. I therefore devoted most of my spare time during 

 the next year to getting together materials and writing the 

 volume, which I finished in the spring of 1898, and it was 

 published in June. The work had a pretty good sale, and at 

 the request of my publishers I prepared from it a School 

 Reader, with a considerable number of illustrations, which 

 was published in 1901. This suggested the idea of a much 

 enlarged and illustrated edition of the original work, which 

 was, as regards 'many of the more important sciences and 

 arts, a mere outline sketch. Almost all the year 1902 and 

 part of 1903 was occupied in getting together materials for 

 this new work, as it really was, and it was not published till 

 the autumn of the latter year. 



But while I was writing three new chapters on the 

 wonderful astronomical progress of the latter half of the 

 century, the startling fact was impressed upon me that we 

 were situated very nearly at the centre of the entire stellar 

 universe. This fact, though it had been noted by many of 

 the greatest astronomical writers, together with the indications 



myopic, though otherwise strong, but in 1883 I did a great deal of work at night, 

 requiring a continual reference to several books of different-sized print, and this 

 brought on rather severe inflammation of the retina, which necessitated a darkened 

 room for some weeks, and no reading or writing for several months — a tremendous 

 trial to me, so that I was able to do no literary work in 1884. The occulist I con- 

 sulted told me that with care in two or three years my eyes would be as strong as 

 ever ; and they very gradually became so, and I had no further trouble till 1891, 

 when some irritating substance got into my left eye and could not be got out, 

 causing severe inflammation for some weeks, which, however, passed away without 

 immediate bad results. From that time, however, there began a loss of the power 

 of adjustment of the two eyes, so that I saw distant objects double, and this has 

 increased so that I now see everything double, even at the other side of a room ; 

 but this does not much inconvenience me except to produce a general indistinct- 

 ness of objects. Two persons walking together on the other side of the street 

 seem to me to be three or four persons, according to the angle of sight, and I often 

 have to shut one eye in order to be sure how many there are. The divergence 

 has now, I think, got to the worst, as I perceive no difference during the last 

 few years. 



