36 A CENTURY'S PROGRESS IN ASTRONOMY. 



he named " star -gauging," consisted in count- 

 ing the number of stars in the telescopic field. 

 Totally he secured 3400 gauges. His studies 

 showed that in the region of the Galaxy the 

 stars were much more numerous than near the 

 galactic poles. Sometimes he saw as many as 

 588 stars in a telescopic field, at other times 

 only 2. He remarked that he had " often 

 known more than 50,000 pass before his sight 

 within an hour." Assuming that the stars were, 

 on the average, of about the same size, and 

 scattered through space with some approach to 

 uniformity, Herschel was unable to compute the 

 extent to which his telescope penetrated into 

 space ; and, assuming that the Universe was 

 finite and that his " gauging- telescope " was 

 sufficiently powerful to completely resolve the 

 Milky Way, he was enabled to sketch the shape 

 and extent of the Universe. 



Thus Herschel concluded that the Universe 

 extended in the direction of the Galaxy to 850 

 times the mean distance of stars of the first 

 magnitude. In the direction of the galactic 

 poles the thickness was only 155 times the dis- 

 tance of stars of the same magnitude. Herschel 

 was thus enabled to sketch the probable form 

 of the Universe, which he regarded as cloven at 

 one of its extremities, the cleft being represented 



