14: J. D. Dana — History of the Changes in Kilauea. 



It also follows that in future reductions of these stone-fall 

 observations it will be better to assume that the velocity of the 

 stone in its orbit was not that velocity which corresponds to a 

 parabolic orbit, but that which corresponds to the mean orbit 

 of the comets of short period. The largeness of the perihel- 

 ion distances has an evident bearing also upon the idea that 

 these stones form the fuel of the sun. 



• The presentation of the argument here made has been in- 

 complete in that the details of the investigation of individual 

 stonefalls has been entirely omitted. Some of the determina- 

 tions of the paths are, I think, as complete as I can hope to 

 make them. But others must be regarded as provisional, since 

 I hope to secure respecting them additional data. I hope at 

 some future time to give a complete discussion of all these ob- 

 served stone-falls. In the past I have been greatly indebted to 

 friends for aid in collecting accounts of the falls, and I heartily 

 thank them therefor. I shall be very grateful also in the future 

 for unpublished observations of the stone-falls, as well as for 

 observations that have been so published as not to be likely to 

 have attracted attention. I bespeak the kindly aid of any who 

 have made or have collected such observations. 



Art. II. — History of Changes in the ML Loa Craters ; by 

 James D. Dana. With Plates I, II, III. 



[Continued from page 289 ; and also from xxxiii, 433, xxxiv, 81, 349, xxxv, 15, 181.] 



Supplement to the Histoky of Kilauea. — Since the debris- 

 cones of Halema'uma'u, the great lava-lake of Kilauea, have a 

 constitution and history unlike anything thus far reported from 

 other volcanic regions, I add to the previous notes the following 

 from a recent letter of Mr. J. H. Maby, of the Volcano House, 

 dated March 8th. Mr. Maby writes that the cone has been ris- 

 ing since August, of 1887, until now the summit is "on a line 

 with the outside walls of the crater, looking from the Volcano 

 House." No additions have been made to the exterior, but in- 

 stead, the eastern side (which Plate 5 in the last volume, from a 

 photograph, showed to be in process of separation from the rest) 

 "has slipped down a little and changed considerably its shape." 

 Moreover the bottom or floor of the Great Lake with its lavas, is 

 now within 40 or 50 feet of the top, which implies a rise of 30 or 

 40 feet in the same interval. The fires have been very active, 

 and are now visible, from the house, on the east side of the cone ; 

 and the lavas on that side have flowed over into the deserted 

 basin of New Lake, filling its lower portion. The lake on the 

 west side of the cone has also much increased in size, being now 

 nearly 300 feet in diameter; and it has thereby encroached on 

 the doomed cone. 



