MIRACLES OF SCIENCE 



estimates were based on 302 spectrograms made 

 between February 1906 and May 1908, Professor 

 Turner tells us that the final most probable value of 

 the solar parallax (which is the astronomical way of 

 stating the case) was 8.800 seconds of arc, with a 

 possible variation of 0.006 seconds. This agrees re- 

 markably well with the value of the reports made in 

 February 1912, by Professor A. R. Hinks from a later 

 discussion of some hundreds of plates of the planetoid 

 Eros taken at twelve observatories during the so-' 

 called opposition of that body in 1900-1901; this value 

 being 8.807 seconds, with a possible variation of 

 0.0027. 



Being interpreted in terms more comprehensible 

 to the average mind, this means that the earth's mean 

 distance from the sun is known within about 30,000 

 miles, a figure which seems infinitesimal in com- 

 parison with the actual distance of almost ninety- 

 three million miles; the variation being equivalent to 

 only twenty inches in a mile. The best determina- 

 tions made from Mars had left a possible variation 

 of a million miles; and Professor Gill's most accurate 

 measurement of the minor planets available before 

 the discovery of Eros still allowed an uncertainty of 

 100,000 miles. 



But even the new figure does not satisfy the 

 astronomers; and Professor Turner tells us that a 

 programme now under way at the Cape Observatory 

 has to do with the observation of 365 stars and that 

 when completed the radial value of at least fifty stars, 

 observed near quadrature of the sun, suitable for the 

 Determination of the solar parallax, will give us "in 



So 



