Francis Cranmer Penrose. 307 



Saturn on that occasion. But it was not till 1852 that any decided 

 move in that direction took place. I had bought a theodolite, chiefly 

 for use in the accurate measurements of the height of buildings, 

 which I had previously essayed by various approximate methods of 

 triangulation, and on showing this instrument to Dr. G. Boole, Pro- 

 fessor of Mathematics to Queen's College, Cork, who happened to pay 

 me a visit, he pointed out to me the interest it would add to what I 

 proposed to do if I turned it also to the heavenly bodies. After this 

 I frequently used it for questions of accurate orientation and time. 

 For instance, the establishment of sun-dials in connection with some 

 of the buildings in which I was professionally engaged gave me 

 occasional opportunities for bringing theory into practice. In 1862 

 I bought a small astronomical telescope, and four or five years after- 

 wards a larger one (5^-inch object glass by Steinheil), equatorially 

 mounted by Simms, of London. In 1866 I happened to see an occul- 

 tation of Saturn by the Moon, in Scotland, for which the predicted 

 time in the Nautical Almanac was not of much use, especially as it 

 was only partially visible at Greenwich, and I endeavoured to obtain, 

 by graphical construction, a more exact correspondence, suited to the 

 site I was then occupying. This first essay was attended with suffi- 

 cient success to lead me to go into the subject more deeply, and 

 ended in my bringing out a book on the Prediction and Reduction of 

 Occultations and Eclipses (4to, Macmillan, 1869), a book which has 

 been sufficiently sold to run itself out of print, though not enough to 

 invite a new edition.* In 1870 I went to the South of Spain to 

 observe a total eclipse of the sun at Jerez, and was introduced to 

 Professor Young and some other American astronomers who were there 

 established for the occasion. I had proposed to view the eclipse with 

 my smaller telescope (2^-inch object glass), and to make an eye drawing 

 of the corona, and I placed myself on an eminence in the famous vine- 

 yard of Macharnudo. I saw the approach of the Moon over the 

 rapidly-diminishing sickle of sunlight till about one minute before 

 totality, when a cloud intervened, and I had to content myself with 

 the terrestrial effects, which, however, I thought striking enough to 

 repay the trouble I had taken. Eight years afterwards an opportunity 

 presented itself to join an eclipse party, which went to Denver, in Central 

 North America, and I there again met Professor Young, and made 

 several new astronomical acquaintances. Everything was favourable 

 for the observation of this wonderful phenomenon. My report of 

 what I saw has been published in the official United States book, 

 giving an account of that eclipse, July 29, 1878; (Washington Obser- 

 vations, Appendix III, 4to, Washington, 1880). After this I extended 



* A second edition was published in 1902. 



