and his son, great as they were in their special department of science, took care to cultivate their minds generally; were mathematicians, chemists, geologists, and men of letters.  And here is a lesson for our younger readers.  The mind should always be diverted towards one particular object; it should be the aim of everybody to attain towards supreme excellence, if possible, in some one pursuit.  On the other hand, he should gather knowledge, more or less, in every field, so as to avoid narrowness of view and poverty of idea.  Versatility does not necessarily mean superficiality; we may know much of many things, and more of one thing.  A man who is only a botanist, shuts himself out from all the truest and deepest pleasures of knowledge.  It may be very clever for a violinist to play on a single string; but he must play on all, if he would bring out the full harmonies of his instrument, and do justice to its extraordinary powers.

* * * * *

Miss Herschel’s enjoyment of life, which, when not carried to an excess, is a Christian duty, continued to the very last.  When she was in her ninetieth year, she rose as usual every day, dressed, ate, drank, rested on her sofa, read and conversed with her numerous visitors; still taking an interest in science and literature, even in public affairs, and still occupying herself with all that concerned the evergrowing reputation of her nephew.  Of course, she could not escape the infirmities of old age, but by cheerfulness and patience she did her best to alleviate them.  In recalling incidents of her early life, she frequently gave evidence of her good-humoured contentment.  In 1840, writing to her niece, she refers to an incident which occurred in the early part of the forty-foot telescope’s existence, when “God save the King” was sung in it by her brother and his guests, who rose from the dinner-table for the purpose, and entered the tube in procession.  She adds that among the company were two Misses Stows, one of whom was a famous pianoforte player; some of the Griesbachs (well-known musicians), who accompanied on the oboe, or any instrument they could get hold of; and herself, who was one of the nimblest and foremost to get in and out of the tube.  “But now,” she adds, “lack-a-day!  I can hardly cross the room without help.  But what of that?  Dorcas, in the Beggar’s Opera, says, ‘One cannot eat one’s cake and have it too!’”

She relates, in the same letter, a curious anecdote of the old and celebrated tube.  Before the optical apparatus was finished, many visitors took a pleasure in walking through it,—­among the rest, on one occasion, King George III. and the Archbishop of Canterbury.  The latter following the king, and finding it difficult to proceed, his majesty turned and gave him his hand, saying, “Come, my Lord Bishop; I will show you the way to heaven!”

Then, with that astonishing memory of hers, which kept its greenness until the very last, she notes that this occurred on August 17, 1787, when the King and Queen, the Duke of York, and some of the princesses were of the company.