In the following table of observed positions of sun-spots, the time given is Clinton mean time (astronomical) for 
the civil date. The first column gives the current designation of the spot by a letter, as used on the author’s draw¬ 
ings and chronograph records. Capital letters are used for groups, small letters for spots, letters with subscripts for 
different nuclei within the same penumbra, letters with exponents for different spots in the same group; a letter with¬ 
out exponent or subscript is assigned to the most conspicuous spot of the group. A a is the observed difference in time 
between the transit of the spot and the mean of the transits of the limbs, or is the difference of right ascension of spot 
and center of disk. A8 is the corresponding difference in declination. In cases of large nuclei, the edges were often 
observed, designated by n and s for declination; the means of the A a and AS were then used in the computations. 
The size of the nuclei may be derived from these data. Measures were also frequently made on the margins of the 
penumbrae, but heliographic positions were not computed, and those measures, as well as the very infrequent meas¬ 
ures of faculae, have been here omitted. The heliographic latitude is given in the next column under the heading b. 
In the column headed L is found the longitude from the node; under U , the heliographic longitude. The letter in 
the last column serves to identify the spot on the next following date. In cases where the identification was regarded 
as doubtful by author or editor, the letter has been omitted. 
The gap in the observations from August 17, 1863, to November 2, 1864, is not due to a deficiency in the records, 
but to a prolonged absence of Dr. Peters in Europe. 
