( 593 ) 
At the outset I think I ought to observe that this hypothesis, 
which is considered by Hate himself, with the laudable caution 
characteristic of him, as still very uncertain *), 1s in a hardly explicable 
contradiction with the equality of the angular velocity of the hydrogen- 
floeculi in every latitude, which Hare has made probable in an 
earlier investigation *). 
For if, between these flocculi and. the spots there is the connection 
that HaLr supposes, we should not expect the same angular velocity, 
at each latitude, but rather very different angular velocities, which 
would have to answer to the great aequatorial acceleration of 
the spots. 
But the hypothesis that the spots are absorbing vortices, has often 
been proposed, but has always turned out very improbable. For a 
vortex leads us to expect first of all that it rotates. But generally 
nothing is seen of this rotation in the spots. CARRINGTON, SrccH1 and 
Youne have more than once intentionally set this forth. According 
to these observers some indication of a cyclonie configuration is 
shown in only 2 or 3 per cent of the spots, and this configuration 
is most times such that it would prove a rotation in opposite 
direction in different parts of a same spot and consequently an 
impossible rotation for the whole spot.*) Moreover Mircuent *) as 
well as Hate and Apams,’*) in their investigations of the spot-spec- 
trum, have found the gaseous substance of the spots generally in 
almost perfect rest. Besides the spots, as a rule, do not seem to be 
concave, but convex. °) 
Although these clear facts, which have been known a long time 
already, make it very improbable that the spots are to be considered 
as absorbing vortices, in Hare’s paper on “Solar Vortices” this 
improbability is demonstrated also in other ways. If there were in 
reality absorbing vortices above the spots, it would be impossible 
1) Hare: Contrib. 26 p. 14. 
2) Hae: Astroph. Journ. April 1908. 
3) Youre: The Sun 1895 p. 126 — Seccur: Le Soleil I. p. 89. 
4) MircHELL: Astroph. Journ. 22 p. 38. 
5) HALE und ApAms: Astroph. Journ. 25 p. 87. 
6) Already at the first discovery of the spots CHRISTOPHORUS SCHEINER drew 
the attention to their often occurring convexity and to their origin as through the 
bursting of bubbles. (Rosa Ursina 1626—1630 p. 461, 493, 513 etc.). See further: 
How.ett: M. N. Dec. 94 -- Sidgreaves M. N. March. 95 — Wirson: M. N. 55 
p. 458 — Frost: Astr. a. Astroph. Il. p. 734 — MAUNDER: Journ. Br. Astr. 
Ass. 17 p. 128 — Corrie: Astroph. Journ. 7 p. 248 — Moreux: Bull. Soc. 
Astr. de France Janv. 1907. 
40) 
Proceedings Royal Acad. Amsterdam. Vol. XI, 
