the Precession of the Equinoxes, 173 



They are all advocates of a central fire, which they pro- 

 bably caught from Newton ; who, in one of his few aber- 

 rations in science, had calculated that the comet of 1680 was, 

 at its perihelion, 2000 times hotter than red-hot iron. Che-^ 

 mistry was then in the infancy in which Boyle had left it, and 

 no one asked himself the question whether comets possessed 

 such a capacity for caloric, or whether the solar rays were 

 really hot. It is very poetical to talk of " The golden orb, 

 pouring forth floods of light through boundless space:" we 

 now know that planetary space is neither warmed nor illu- 

 mined by the solar rays; all is cold* dark night, save within the 

 atmospheres of the planets; there, the solar rays, acting on 

 the atmosphere, produce combustion, from which light and 

 heat are evolved. This is one argument against a central fire : 

 but before I develope the whole of the new theory, I wish 

 the truth of its basis to be brought to the test of actual 

 experiment. 



I have advanced that the ecliptic is a real circle on the 

 earth ; that, by the precession of the equinoxes (arising from 

 the earth's figure) the equator cuts it in a different point 

 every year, returning to the same point in 25,920 years 

 (according to De Lambre). By this motion, the poles of the 

 equator revolve round the poles of the ecliptic on a radius of 

 23° 28^, or about 1400 geographical miles. Thus far astrono- 

 mers agree with me ; and here, I am sorry to say, we part com- 

 pany. They do not admit that this can produce any changes 

 on the earth's surface ; whereas I attribute nearly the whole 

 of them to it, and I will even appeal to them, and them 

 alone, to decide the question. 



Now, if, as I assume, the pole of the equator revolves in 

 the circumference of a circle of 2800 miles in diameter, all 

 churches and buildings erected due north and south, even 

 only one hundred years since, are no longer so ; that no 

 sundial erected the same length of time is at present cor- 

 rect ; that no meridian, traced with care at such a period, is 

 at present true ; that all latitudes and longitudes, determined 

 with the utmost care 50 to 100 years since, differ from those 

 taken by recent observers ; and that it is easy to state before- 

 hand not only on what side the supposed errors lie, but their 

 amount. 



I do not wish to prejudge the question ; as I have already 

 stated, the astronomers shall decide it : but I may be per- 



* The late Baron Fourier, perpetual Secretary to the Royal Academy 

 of Sciences of Paris, calculated planetary space to be 90 degrees below the 

 freezing point of Fahrenheit. 



C^^ 



