CHAPTER XVII.

Former compromises taken up and begun to be fulfilled 301

Estimates of the heat-power of the sun made only from

gravitation hitherto 302

Contraction and condensation of a nebula solid to the

centre. Heat produced from attraction as well as

by gravitation 303

What quantity of heat is produced by a stone falling

upon the earth 304

Showing again that there is a difference between

attraction and gravitation 305

Contraction and condensation of a hollow-sphere nebula,

in the same manner as the solid one 305

Differences of rotation would be greater in a hollow nebula;

because a great deal of the matter would be almost

motionless in a solid sphere 306

In neither case could matter be brought to rest, but only

retarded in motion. Different periods of rotation

accounted for 307

Table of different rates explained 309

Heat produced by gravitation, attraction and churning,

not all constituents of the heat-power of the sun 310

There can be no matter in the sun so dense as water 311

The hollow part of the sun acting as a reservoir of

gases, heat and pressure 312

The behaviour of heat produced in the nebula, and its power 313

How sun-spots are produced 314

Cyclonic motions observed in sun-spots. Why not all in

certain directions, and why only observed in a very few 315

Cyclonic motions in prominences treated of 316

Many other things might be explained, on some of which we

do not dare to venture. Concluding observations 317

New Theories in Astronomy · 第 17 / 23 章