SUNSPOTS AND VOLCANIC AND SEISMIC PHENOMENA. 59 



In the above curves I have written Max., i.e. Sunspot 

 Maximum in period 4 — 5, because the average interval 

 between a minimum and a maximum and the following 

 maximum has during this century been between 4 and 5 

 years. 



VI. Seismic and Volcanic Activity and Moon's Perigee. 

 — To satisfy myself about the above relation, I have 

 catalogued all the earthquakes and eruptions which have 

 taken place, so far as I can ascertain, between April 1st, 

 1902 and December 1903, together with declination and 

 phases of the moon. 



In a letter to the "Scientific American" June 21st, 1902, 

 p. 433, Mr. Elmer J. Still discusses the possibility of fore- 

 casting earthquakes and eruptions from lunar observations. 

 Although it will be noticed that I hinted at the same possi- 

 bility in my paper of June 4th, 1902, it seems that Mr. Still 

 has too much confidence in the moon's capacity to bring 

 about such disasters. Mr. Still points out that seismic and 

 volcanic activity are increased at (a) perigee, (6) new 

 moon, (c) and when the moon crosses the earth's equator. 



According to Mr. Still's scheme there should have been 

 great disturbances on June 13th, 1902, for then the moon 

 crossed the equator ; but the disturbance came on June 

 19th and 20th, at apogee and full moon. Again violent 

 earthquakes might have been expected on October 1st 

 because on September 30th the moon crossed the equator, 

 and on October the 1st it was new. At this time however 

 no great disturbances were reported, whereas on October 

 17th, at full moon, severe earthquakes were widely experi- 

 enced. On October 13th, 1902, however, at new moon, a 

 violent earthquake and volcanic eruption was reported 

 from Savaii in Samoa, the first since 1866. On November 

 13th, again full moon, the volcano Santa Maria in Guate- 

 mala, erupted and covered the towns of Palmar, Columbia, 



