Scientific Intelligence — Hydrography. 403 



every living being creeps to the forest to secrete itself, seeking shelter 

 from the fearful heat ; save that, now and then, an ostrich will be seen 

 traversing the desert fields in flying pace, or a giraffe hastening from 

 one oasis to another. " When I arrived at Lobeid," says the writer, " I 

 only found one single European living, Dr Iken, whom I have before 

 mentioned, a native of Hanover, who, like most of the Europeans, after 

 a short residence there, paid his tribute to the climate." 



HYDROGRAPHY. 



2. Depression of the Caspian. — The President of the Geographical 

 Society of London, in June last, read the note of a Russian operation for 

 determining the actual depression of the Caspian Sea below the level of 

 the Mediterranean — which operation had been reduced by the eminent 

 astronomer, M. Struve, then in England, and communicated by that 

 gentleman to him. A few years ago it was generally believed that the 

 waters of the Caspian were at least 300 feet below the level of those of 

 the Black Sea and INIediterranean. This view was adopted in consequence 

 of a series of barometrical observations ; but it having been found that, 

 from the great number of stations across the land separating the Caspian 

 from the sea of Azoff, small errors had become greatly magnified, a new 

 survey was made. Three able mathematicians, Messrs Fuss, Savitch, 

 and Sabler, were, therefore, employed to make independent trigonometri- 

 cal le veilings ; and their observations agreeing to within a foot or two, 

 give, for the mean result, 83.6 English feet as the depression, the possible 

 error being limited to 1.3 foot, which definitively settles this long pend- 

 ing geographical question. — Athenaum, No. 870, p. 601. 



3. " The Calling of the Sea." — As the foreknowledge of approaching 

 changes in the weather is of importance, especially to fishermen and 

 agriculturists, I invite attention to a very common, but not generally 

 known, indication of such changes. 



In Mount's Bay, and probably in all places similarly situated, there is 

 often heard inland, at a distance from the shore, a peculiar hollow, mur- 

 muring sound, locally termed '* the calling of the sea," which, if proceed- 

 ing from a direction different from the wind at the time, is almost always 

 followed by a change of wind, generally within twelve, but sometimes 

 not until a lapse of twenty-four, or even thirty hours. It is heard some- 

 times at the distance of several miles, although on the shore from which 

 it proceeds, the sea may not be louder than usual ; and yet at other times, 

 even when the sea on the shore is louder than usual, and in apparently 

 equally favourable states of the atmosphere, it cannot be heard at the 

 distance of a mile. When the sound, in fine weather, proceeds from the 

 coves or cliffs on the west or south of the observer, it is followed by a 

 wind from about west or south, accompanied generally with rain. When 

 it comes from tlie east or north of the observer, a land wind from about 

 east or north succeeds, attended with fine weather in summer, and often 

 with frost in winter. All my own observations during the last twelve 

 months, confirm the above statement ; indeed, none of those of whom I 

 Ijave inquired, and who have for many years been accustomed to observe 

 these indications, can recollect a single instance of their failure. This 

 sound must not be confounded with that arising from a *' ground sea," 

 which is the well known agitation along the shore, oec^asioned by a dis- 



