INDUSTRIAL PROGRESS DURING THE YEAR 1875. xxxiii 



One of the most valuable catalogues of nebulae yet pub- 

 lished is that of Schultz, of Upsala, who has observed the ex- 

 act positions of about five hundred of these bodies with ref- 

 erence to neighboring stars, thereby preparing the way for 

 determinations, to be made possibly a hundred years hence, 

 of the proper motions of these nebulae. 



PHYSICS OF THE GLOBE. 



Tides. One of the most useful works that has appeared 

 of late years on the subject of tides has been published by 

 the Coast Survey. Its author, Professor Ferrel, has given in 

 detail the formulae needed in the discussion of lona; series of 

 tidal observations, and has treated specially the subject of 

 shallow water tides. Professor Ferrel has also been able to 

 deduce the mass of the moon with a high degree of accuracy, 

 after taking; account of the influence of friction. 



Mr. Rohrs, in a paper on tidal retardation, has discussed 

 the problem of maximum retardation on a globe entire- 

 ly covered by a sea whose depth is constant for all points 

 in the same latitude, but varies from the equator to the 

 poles. 



Sir William Thomson announces his conclusion that the 

 much-vexed question as to the generality and correctness of 

 Laplace's tidal investigations must be at last decided in favor 

 of that great mathematician, and that therefore Airy's criti- 

 cism falls to the ground, as also that of Ferrel. Airy's reply 

 to Thomson will probably serve to prolong the discussion 

 of this obscure but highly important question. 



Seismology. The investigations of La Saulx upon the 

 earthquakes of Western Prussia have led to the authorization 

 by the Prussian government of the establishment of a large 

 number of seismometric stations in the volcanic region near 

 Bonn. 



Rev. O. Fisher has communicated a paper to the Cam- 

 bridge Philosophical Society, in which he states that his at- 

 tempt is to arrive at more definite conclusions in regard to 

 the elevating force which has raised mountain ranges and 

 caused the wrinkling of the crust of the earth. 



The earthquake phenomena of Southern Austria have been 



elucidated in a valuable memoir by Suess, who shows that 



the centres from which earthquakes emanate are. in that 



2* 



