of these masses must be attended by disturbance of the 

 solar flame. The fresh cosmic fuel before combustion 

 will produce dense smoke, which will be visible from 

 earth in sun-spots, corresponding in size and appearance to 

 the bulk of the burning matter. The changes noticeable 

 follow the results of combustion, and the movement is 

 accounted for partly by the revolution of the sun upon 

 its axis and partly by the unequal flood of gas, which, 

 rousing the solar flames throws them to a greater or a 

 lesser height. Such, in broad terms, is the cause of sun- 

 spots. 



It is remarked that the appearance of spots on the 

 sun is accompanied by atmospherial changes on the earth. 

 The more sun-spots appear, the colder it becomes; the 

 less, the warmer. The year 1894 supplied convincing 

 proof of the intimate connection between the temperature 

 of our globe, and the appearance of these spots. Rarely 

 have so many comets crossed our sky as in that year: 

 As many as three star-comets were remarked, of which 

 two were visible to the naked eye, and in addition to 

 these four large cloud-spots were observed. 



I have just presented the picture of the formation of 

 sun-spots, in the figure of a furnace into which a green 

 bough has been thrown. Let us see what must take place. 



In the first place, wherever the material was thrown 

 a dark smoke would obscure the flame; in the second 

 the temperature of the furnace would immediately sink- 

 as can easily be shown by actual experiment. This 

 occurs in consequence of the fact that the radiant energy 

 previously heating the surrounding air is now centred 

 on the task of heating the fresh fuel to the point of com- 

 bustion. 



Is it not a parallel process we remark in the case of 

 the sun ? All the comets pass across the sun's disc, and 

 in passing leave a mass of cosmic matter, subject to 

 combustion, naturally causing sun-spots, and while these 

 masses are heating, an obstacle is opposed to the diffu- 

 sion of solar heat, the source of planetary warmth. It 



