ïlie distriliution of the stars to the eleventh magnitude 37 



TABLE III. Reduction from square centimeter to square degree. 

 1 square degree = c square centimeter. 



square 





squaie 



c 



.square 





scjnare 



c 



.square 



c 



1,1 



0,332 



5,1 



0,3 tl 



9,1 



0,365 



-3,1 



0,335 



-7,1 



0,351 



1,3 



0,335 



5,3 



0,314 



9,3 



0,368 



-3,3 



0,337 



-7,3 



0,354 



1,5 



0,341 



5,5 



0,350 



9,5 



0,375 



-3,5 



0,344 



-7,5 



0,361 



2,7 



0,351 



5,7 



0,361 



9,7 



0,385 



-3,7 



0,354 





0,371 



1,9 



0,365 





(_),375 





0,400 



-3,9 



0,368 



-7^9 



0,385 



3,2 



0,ci35 



7,2 



0.352 



-1,2 



0,333 



-5,2 



0,3(2 



-9,2 



0,366 



3,4 



0,340 



7,4 



0,357 



-1,4 



0,337 



-5,4 



0,347 



-9,4 



0,371 



8,(; 



0,349 



7,G 



0,365 



-1,G 



0,318 



-5, G 



0,355 



-9,G 



0,330 



3,8 



0,361 



7,8 



0,378 



-1,8 



0,358 



-5,8 



0,367 



-9,8 



0,392 



3,10 



0,377 



7,10 



0,394 



-1,10 



0,374 



-5,10 



0,383 



-9,10 



0,409 



By the helji of thi.s ta))le all the counts have l)een reduced. 



7 Discussion of the Distribution of the Stars on the Plates. 



After having reduced all the counts by the aid of Tab. Ill it is jiossible to discuss 

 the distribution of the stars on the negatives. 



Nearly all the plates show tlie fact that the density, accidental condensations 

 apart, decreases from the centre of the plate towards the margins. 



In order to make this more elear and to get a numerical expression for the 

 decrease I proceed in this manner: 



I divide the plate into seven zones by concentric circles liaving the radii 2, 4, 

 ... 12, 14 centimeters. Within each of these zones I calculate tlie average density. 

 The number of observations in the zones are: 



Zone 1 4 observations. Average density = 



— 2 10 — _ __ = j;^ 



— 3 18 — - — = B., 



— 4 24 — — - - = 



— b 2S - - - = D, 



— 6 14 — _ = x>,, 



The entire plate 100 — ~ = D^, 



These quantities have been calculated for the whole set of plates and are given 

 in Tab. IV. 



