THE SUN AND PHENOMENA OF ITS SURFACE. 69 
the last of August. Between 8 o’clock of 28th and the same hour of 2oth, a 
very large spot broke up and formed three smaller ones. In three or four days 
after this wreck in the sun, a great rain fell in our country. Very few spots in 
September. But a large cluster was very prominent from October 7th to rth. 
In a few days other spots broke out in different places, making a speckled ap- 
pearance on the sun’s face. About the 21st they had all disappeared, leaving 
the sun clear for two weeks, and nearly so for three weeks. Toward the middle 
of November a large group formed and passed over the western side of the sun. 
A few small spots on several days in December closed the exhibition for 1879. A 
show of fifty-five spots in three groups occurred in the middle of January, 1880; 
and since that time but few days have passed without spots being present on the 
sun. So it is evident that they are now on the increase. AndIam not sure 
but that it is more rapid than it was in the early part of the period which com- 
menced in 1867. I consider that the minimum this time occurred in the early 
part of 1879; making the period twelve years long. 
About eleven years is the average length of several former periods from one 
minimum to the next. The extremes are about ten and thirteen years. 
Greater activity seems to prevail during the first half of the period than 
during the last half, so that the maximum, or greatest show of spots, occurs 
about two years before the middle of the period. But Iam satisfied from my 
own observations that the maximum of the last period was near three years be- 
fore the middle, particularly as regards the number. However, spots of large 
size continued two or three years after their number began to grow less. 
In attempting to explain the freckly or mottled appearance, I would offer 
the one theory of its being the interstices of the darker or gray portion of the 
sun’s surface in which a very large telescope, furnished with a polarizing eye- 
piece, shows ‘‘hundreds of thousands of small intensely brilliant bodies, that 
seem to be floating in the gray medium, which, though itself no doubt very 
bright, appears dark by comparison. What these little things are, is still uncer- 
tain; whatever they are, they are the immediate principal source of the sun’s 
light and heat.” They bear a certain resemblance to rice grains of different 
size and shape. Although these little bodies appear quite small when they are 
magnified even many hundred times, yet they are really hundreds of miles in ex- 
tent. It is believed that these little fiery bodies collect in dense masses and form 
the cloud-like faculze which often appear near the edge of the sun, and are apt to 
precede the formation of large spots, though not in every case. These facule 
are often so large and prominent as to be visible through a telescope of 114 or 2 
inches aperture. Huyghens said of them near two centuries ago, that they seem 
to be ‘‘something in the sun brighter than the sun itself.” 
) It is now a settled belief among those who have given the subject most at- 
tention, that iron, magnesium, and other metals exist in the sun, and particularly 
in the region of the spots; though not in the solid state in which we know them, 
nor even in the melted or liquid condition, but in.the form of gas, or vapor— 
