FORMAL ASTRONOMY. 527 



Description of Books'' (1853) ; "The Progress of the Doctrine of the 

 Earth's Motion between the Times of Copernicus and Galileo" (1855). 

 In these papers he insists very rightly upon the distinction between 

 the mathematical and the physical aspect of the doctrines of Coperni- 

 cus : a distinction corresponding very nearly with the distinction which 

 we have drawn between Formal and Physical Astronomy ; and in ac- 

 cordance with which we have given the history of the Heliocentric 

 Doctrine as a Formal Theory in Book v., and as a Physical Theory in 

 Book vii. 



Another interesting part of Mr. De Morgan's researches are the no- 

 tices which he has given of the early assertors of the heliocentric 

 doctrine in England. These make their appearance as soon as it was 

 well possible they should exist. The work of Copernicus was pub- 

 lished, as we have said, in 1543. In September, 1556, John Field 

 published an Ephemeris for 1557, "juxta Copernici et Reiuholdi Ca- 

 nones," in the preface to which he avows his conviction of the truth ot 

 the Copernican hypothesis. Robert Piecorde, the author of various 

 works on Arithmetic, published among others, "The Pathway to 

 Knowledge" in 1551. In this book, the author discusses the question 

 of the " quietnes of the earth," and professes to leave it undecided 

 but Mr. De Morgan (Comp. A., 1837, p. 33) conceives that it appears 

 from what is said, that he was really a Copernicau, but did not think 

 the world ripe for any such doctrine. 



Mr. Joseph Hunter also has brought to notice 1 the claims of Field, 

 whom he designates as the Proto- Copernican of England. He quotes 

 the Address to the Reader prefixed to his first JZpkemeris, and dated 

 May 31, 1556, in which he says that, since abler men decline the task. 

 "I have therefore published this Ephemeris of the year 1557, follow- 

 ing in it as my authorities, N. Copernicus and Erasmus Reinhold, 

 whose writings are established and founded on true, certain, and au- 

 thentic demonstrations." I conceive that this passage, however, only 

 shows that Field had adopted the Copernican scheme as a basis for 

 the calculation of Ephemerides ; which, as Mr. De Morgan has re- 

 marked, is a very different thing from accepting it as a physical truth. 

 Field, in this same address, makes mention of the errors "illius turbce 

 qua? Alphonsi utitur hypothesi ;" but the word hypothesis is still inde- 

 cisive. 



As evidence that Field was regarded in his own day as a man Avho 



- Asi. Soc. Notices, vol. iii. p. 3 (1S33). 



