Their married life lasted 45 years, but the last six years were saddened by the partial paralysis and serious illness of Lady Airy. The entire correspondence between them was most carefully preserved, and is a record of a most happy union. The letters were written during his numerous journeys and excursions on business or pleasure, and it is evident that his thoughts were with her from the moment of their parting. Every opportunity of writing was seized with an energy and avidity that shewed how much his heart was in the correspondence. Nothing was too trivial or too important to communicate to his wife, whether relating to family or business matters. The letters on both sides are always full of affection and sympathy, and are written in that spirit of confidence which arises from a deep sense of the value and necessity of mutual support in the troubles of life. And with his active and varied employments and his numerous family there was no lack of troubles. They were both of them simple-minded, sensible, and practical people, and were very grateful for such comforts and advantages as they were able to command, but for nothing in comparison with their deep respect and affection for one another. Both by natural ability and education she was well qualified to enter into the pursuits of her husband, and in many cases to assist him. She always welcomed her husband's friends, and by her skill and attractive courtesy kept them well together. She was an admirable letter-writer, and in the midst of her numerous domestic distractions always found time for the duties of correspondence. In conversation she was very attractive, not so much from the wit or brilliancy of her remarks as from the brightness and interest with which she entered into the topics under discussion, and from the unfailing grace and courtesy with which she attended to the views of others. This was especially recognized by the foreign astronomers and men of science who from time to time stayed as guests at the Observatory and to whom she acted as hostess. Although she was not an accomplished linguist yet she was well able to express herself in French and German, and her natural good sense and kindliness placed her guests at their ease, and made them feel themselves (as indeed they were) welcomed and at home.