148 Mr. Schroeter's new Observation? 
horns a, b, for the foundation of my measurement, I measured 
likewise the two lines af, b g, perpendicular on the line of the 
cusps. I found the northern side/ a = S lines — 32", the south- 
ern only fully 7 to lines; mean, 7,25=29"; consequently 
both sides together/ a -j- b g = 61", therefore the mean of each 
side = 30", 5 ; but if the southern side b g be put~= 7,5 lines, 
the mean will be fully = 31" ; so that, as the semidiameter, ac- 
cording to the first measurement, could amount only to 30", I 
probably observed the cusps as projecting o",5, and perhaps 
something more, beyond their proper line ;* and consequently 
the projection of the' crepuscular light, which extended into the 
dark hemisphere, was certainly and at least as 1 : 6 in propor- 
tion to the apparent diameter. 
My success in this measurement was the more lucky, as 011 
the 22 d of May Venus could no longer be discerned, though 
the air was clear. , 
These are my late observations, made about the time of the 
greatest eastern elongation, in the year 1793 ; and continued 
three months to the inferior conjunction. Under my present 
circumstances, I hope to be excused for giving them with 
such prolixity ; but I should quite weary the reader, were I now to- 
lay before him likewise my further observations, continued to 
the last western elongation ; which, therefore, I shall rather 
reserve to another occasion, especially as they contain little 
that is interesting. 
However, I must not leave unnoticed some conclusions, 
remarks, and explanations, which are deducible from these 
observations ; and which have for their object, partly the moun- 
* The remarks and computations that follow hereafter, will shew that the penumbra 
was probably included in the measurement. 
