ON XIIE VOLCANIC PHENOMENA OF VESUVIUS. 473 



lively display for nearly an hoar we were at last rewarded by the spiracle 

 clearing its throat of this obstruction, and its puffing became much more 

 regular, softer, and more constant. I secured this expectorated ball which 

 the spiracle had been so long in ejecting, and after allowing an hour for 

 it to cool brought it home as an addition to my collection. I found 

 round this spiracle several other such balls some 15 to 20 cm. in diameter, 

 showing that the process had been repeated several times. The balls 

 might be well taken for the so-called bombs, and is an explanation of a 

 new though unimportant source of some of the structures included under 

 the indefinite term of volcanic bomb. 



It is deeply to be regretted that the numbering of the dykes in the 

 Atrio del Cavallo, which cost so much labour and even money, is rapidly 

 disappearing. 



Campi Phlegraei. — The tunnel for the upper sewer in Naples has 

 traversed the trachyte and entei-ed a series of tuffs ; but I propose to 

 treat of these, as well as the peculiar piperno-like deposit of the Corroglio 

 sewer, in another report or elsewhere, as the work is not yet quite 

 complete. Here the peculiar piperno-like deposit has been traversed and 

 a yellow tuff" reached. 



Few facts of importance, either of a local or general vulcanological 

 interest, have during the year come to light; but while in Naples I 

 continue to keep a sharp look-out, and record any facts of interest. 



The reporter has to state that most of his available time during last 

 winter was occupied in working out the eozoonal-like structures of the 

 altered limestones of Monte Somma, a memoir on which subject has 

 been presented to the Royal Dublin Society by Dr. J. W. Gregory and 

 himself, in which they hope to have proved that these structures are all 

 the result of metamorphism. 



The Collection, Presei^ation, and Systematic Registration of 

 Photographs of Geological Interest in the United Kingdom. — 

 Fourth Report of the Committee, consisting of Professor James 

 Geikie (Chairman), Professor T. G. Bonney, Dr. Tempest An- 

 derson, Dr. Valentine Ball, Mr, James E. Bedford, Professor 

 W. Boyd Dawkins, Mr. James W. Davis, Mr. Edmund J. Gar- 

 wood, Mr. William Gray, Mr. Egbert Kidston, Mr. Arthur 

 S. Eeid, Mr. E. H. Tiddeman, Mr. W. W. Watts, Mr. Horace B. 

 Woodward, and Mr. Osmund W. Jeffs {Secretary). (Drawn 

 up by the Secretary.) 



YouK Committee have the honour to append to this their fourth report 

 a. list of geological photographs added to the collection during the past 

 year. The number shows an increase as compared with the previous 

 year, and probably indicates the average number now to be expected 

 within a similar period, if the operations of the Committee be continued. 

 For the greater part, the photographs included in the present list are 

 recent, having been taken during 1892-93, while those inserted in previous 

 lists included a number which were photographed some years ago. It 

 may be concluded that, among photographs of older date, the most 



