cal and the jet of water had reached a height of about 70 feet. 

 Another picture, taken after L\5 seconds, showed a water column 

 160 feet high ; and a third, 2-3 seconds after the explosion, showed 

 the jet at its maximum height of 180 feet, the air being full of 

 fragments not yet descending. At the end of 4-3 seconds all 



4. /Vwi.«;„„.// ,„/,„,* ,./■ the Signal Service.— The U. S. Sig- 



valuable series of papers under the above title. The first num- 

 ber is by Professor Abbe and consists of the Signal Service 

 Reports on the Total Solar Eclipse of July, 1878. The second is 

 a series of twelve maps of the monthly isothermal lines deduced 

 from the observations of the years 1871-80, by Lieutemmt A. W. 



(Jree 



ley. The thi 



r«l is 



a eh'i 



onoloo-ical list 



of Aurora 



s observed 











> Lieutenant A. 



, W. Greeley. The 



fifth 



is on the coi 







ind maintenanc 





halls, and 



conti 



doe ten or ti 



.velve 



letters of persons w 



ho hav | 



iad special 



expei 



■ience in managing 







The sixl 



h pape.M> 



bv .M 



r. H. A. Ha 





. the 



reduction of ai 







leVe) 



at elevated st 







of the Mississ' 



/ .\/i'/iii/i<> 





5. 



Celebrated A; 







vents, expt'ciaU; 



't/i, Wt,tni- 





ltd LtO'Kj/, to; 



,ethtr 











o.Vs"'! 



1'^s'vo''' wi't'l 



1 ,j,;>t, 



';;;; 



I'^iUnM rations'" 



^ 'c'meuin 



Mi llt iZt. 



ll"iob : 



eri Cla'rke A; 



Co.)- 



The; 















. He 







th-rudy 



and 









thev afford, t 



he disco ve 





15 



ges, and the 



exanii 



natioi 



i of "the variou 



s objects 



o'f interest 



e way ; and 1 







iderings have e: 



itended to 







lis besides tli 





entioi 





, Mn,eo\ 



•er, in the 



gathered material from 



s through so great 

 wrist, for which he bi 



difficult problem to the geologist, 



most general explanations — such as are contained in a referem 

 to joints; bedding, harder and softer or impurer layers alternatin; 

 erosion by corroding carbonated waters, by direct abrasion, ai 

 to some extent through nitrification and the products of pvritt 

 decomposition. The facts of scientific interest are partly given 

 Mr. Hoyey's paper in volume xvi (1878) of this Journal. Lun 

 cavern in Luray Valley, near the village of Luray, Page Count 

 Virginia, was little explored or known before 1878. It is mu( 



