474 SCIENTIFIC RECORD FOR 1883. 



for this purpose, and the positions of Callao, Lima, Payta, Arica, and 

 Valparaiso were carefully fixed, tbe latitude of each station being de- 

 termined by the zenith telescope. Lieutenant-Commander Davis con- 

 nected his chain of longitudes at the northern end with the station at 

 Panama telegraphically determined in 1874 by Lieutenant-Commander 

 Green, U. S. N., and at the southern end with the observatory at Cor- 

 doba, fixed in the same manner by Dr. B. A. Gould. This great work, 

 which has been admirably executed, completes an enormous polygon or 

 telegraphic chain of longitudes from Greenwich by way of Washington, 

 Havana, Panama, Valparaiso, Cordoba, Buenos Ayres, Rio de Janeiro, 

 Madeira, and Lisbon, back to Greenwich. 



EUROPE. 



A comprehensive idea of the work in progress by the Government 

 surveys of the different countries in Europe is derived from the reports 

 of the meetings of the International Geodetic Association. The pro- 

 ceedings at the annual meeting at The Hague in September, 1883, have 

 recently been published, and are summarized by Mr. C. A. Schott in 

 Science for November 1G, 1883. The countries represented and from 

 which reports of progress were received were Baden, Bavaria, Denmark, 

 France, Hesse, Holland, Italy, Austria, Portugal, Prussia, Eoumania, 

 Russia, Saxony, Switzerland, Spain,Wurtemberg, Belgium, and Norway. 

 Among the many interesting matters referred to in the reports of prog- 

 ress the most striking is the demonstration that the average level of the 

 Mediterranean is lower than the Atlantic by about two feet and one 

 inch (0.64 meter). This conclusion had beeu stated by M. Bourdalou, 

 in 1864, in his work Nivellements generate de la France, but was not gen- 

 erally credited. 



In levelling across from the Atlantic to the Mediterranean the follow- 

 ing differences in average level have been found : 



Meter. 



Between Santander and Alicante 0. 662 



Swinemunde and Marseilles by way of Switzerland 0. 664 



Swiueniunde to Marseilles by way of Amsterdam 0. 658 



Amsterdam and Trieste 0. 590 



ASIA. 



A very serious change has been effected in the eastern part of the 

 island of Java and the neighboring islands by the volcanic upheaval 

 of August, 1883. The small uninhabited island of Krakatoa, lying 

 about the middle of the straits of Sunda, an important commercial 

 passage between the islands of Java and Sumatra, was, at the time 

 of the first obtainable accounts of it (A. D. 1681), in a state of erup- 

 tion. The present eruption commenced on the 21st of May and con- 

 tinued with great activity for eight or nine weeks, until the evening of 

 August 26 and the morning of August 27, when tremendous explosions 

 followed in rapid succession, tearing away and throwing into the sea a 



