January 25, 1894] 



NA TURE 



301 



can be done by having a slit and photographic lens fixed and 

 placing the sensitised plate upon the carriage of a dividing 

 engine. The plate is moved along with the carriage, and when 

 it has been exposed to the slit a desired number of times it is 

 developed and fixed, the result being a photographic grating. 



GEOGRAPHICAL NOTES. 



A TELEGRAM from Zanzibar, dated January l6, states that 

 over a hundred deserters from Mr. Astor Chanler's expedition 

 had reached the coast and reported that he was left with only 

 eighteen men at Daicho. It has already been mentioned 

 (Nature, vol. xlix. p. 112) that the expedition was deprived 

 of Lieutenant von Hohnel's services, by an accident. We trust 

 that Mr. Chanler may be able to reorganise his expedition, and 

 push into the unknown country on the borders of which he has 

 been so long detained. 



The Times correspondent at St. Petersburg states that Mr. 

 F. G. Jackson, after testing his sledges and other appliances in the 

 neighbourhood of the Yugor Strait, is returning 10 England via 

 Lapland, and that he has not been in the Yalmal peninsula. 

 The proposed North Polar expedition via Franz Josef Land, 

 will be, if it starts, as is expected, this year, the fourth in the 

 field. The others are the private American expedition under 

 Mr. Peary, working from the north of Greenland ; the private 

 Norwegian expedition of Mr. Ekroll, which left the north coast 

 of Spitzbergen in summer, relying on a new convertible sledge- 

 boat ; and Yir. Nansen's expedition, drifting northward from the 

 neighbourhood of the New Siberian Islands. 



The death is announced, on January 20, of General SirC. P. 

 Beauchamp Walker, the Foreign Secretary of the Royal Geo- 

 graphical Society. 



The memory of Prince Henry the Navigator, to whose per- 

 sistent efforts the modern revival of oceanic exploration was 

 mainly due, is to be honoured by the celebration of the 500th 

 anniversary of his birth, in March, with great festivities at 

 Oporto. The proceedings will to a certain extent resemble the 

 Columbus celebration recently held in Spain. The event they are 

 to commemorate was even more important, since the Portuguese 

 explorers, as a direct consequence of the encouragement of the 

 half-English prince, discovered the ocean-road to India, and 

 incidentally the coast of South America also, independently of 

 the Spanish voyagers who followed in Columbus' track. 



Several recent experiments on oceanic currents by means of 

 floats have been noticed in the newspapers within the last fort- 

 night. Mr. J. E. Muddock states in the Times that a corked 

 soda-water bottle containing an addressed slip of paper which 

 was thrown overboard by him off the entrance to the Strait of 

 Belleisle, on July 12, 1892, was picked up on November 28, 

 1893, on the Norwegian coast near Kvarno, in latitude 61° 4' 

 N. The bottle was launched farther north than any of those 

 placed in the water by the Prince of Monaco, but there is no 

 clue to its course beyond that of the time elapsing before it was 

 found, 485 days. Mr. Muddock assumes that the drift was 4000 

 miles, but the direct distance by sea is only 2500 miles, although 

 it is probable that the bottle drifted south in the Labrador 

 current before turning north-eastward with the Gulf Stream. 

 Mr. Ballingall, of Largo, writes to the Scotsman that he launched 

 a cork-covered bottle at Largo, on the Firth of Forth, on 

 November 22, which was picked up at Akre, on the Norwegian 

 coast (lat. 59° 19'), 460 miles distant, on December 29. Being 

 only thirty-seven days in the water, the bottle must have drifted 

 at the rate of not less than twelve miles a day. The bottle pro- 

 bably floated high and was helped by westerly winds ; but in 

 any case the rate of movement is rapid, and if the direction of 

 the current was that usually assumed, first southward, then 

 east, and finally north, the velocity is very remarkable. 



EARTH MOVEMENTS. 



T7 VERY year, every day, and possibly every hour, the physi- 

 -^-^ cist and observer of nature discovers something which 

 attracts attention, causes wonder, and aftords material for dis- 

 cussion At one moment we are invited to see solidified air, 

 at another to listen to telephonic messages that are being trans- 

 mitted without a wire, or to pause with astonishment before a 



NO. 1265, VOL. 49] 



pen which is producing a fac-simile of the writing, the sketches, 

 and the erasures of a person who may be in a distant city. Not 

 a day passes without a new creation or discovery, and novelties 

 for our edification and instruction are brought to our notice at 

 the meetings of societies and conventions which from time to 

 time are held in various parts of the world. At the last meeting 

 of the British Association, held in Nottingham, the attention of 

 members was called to the reports of two committees summaris- 

 ing a series of facts which seem destined to open a new field in 

 the science which treats of movements in the crust of our earth. 

 For thirteen years one of these committees has devoted its 

 attention to the volcanic and seismic phenomena of Japan, with 

 the result that our knowledge of these subjects has been con- 

 siderably extended. Now we observe that earthquakes, which 

 are referred to as catastrophes in the processes of mountain 

 formation and the elevation or depression along our coast-lines, 

 are spoken of as "vulgar disturbances" which interfere with 

 the observation of certain earth movements which are probably 

 as common to England as they are to Japan. 



Earthquake observations, although still capable of yielding 

 much that is new, are for the present relegated to a subordinate 

 position, while the study of a tide-like movement of the surface 

 of our earth, which has been observed in Germany and Japan, 

 earth tremors, and a variety of other movements, which we 

 are assured are continually happening beneath our feet, are to take 

 their place. Only in a few countries do earthquakes occur with_ 

 sufficient frequency to make them worthy of serious attention. 

 The new movements to which we are introduced are occurring 

 at all times and in all countries, and we are asked to picture 

 our continents as surfaces with a configuration that is always 

 changing. We are told that every twenty-four hours the ground 

 on which we live is gently tilted, so that the buildings in our 

 cities, and the tall chimneys in our manufacturing towns, are 

 slightly inclined like stalks of corn bent over by a steady breeze. 

 The greatest tilting takes place during the night ; in the morning 

 all return to the vertical. 



Why such a movement should exist, we are not told. All that 

 we hear, is that it is too large for a terrain tide produced by lunar 

 attraction. In Japan it appears possible that it may prove to 

 be a concertina-like opening and shutting of the crumpled 

 strata forming a range of mountains. To determine whether 

 this intermittent puckering of strata, which would mean a daily 

 increase and decrease in the height of mountains, explains the 

 variability in the level of districts where observations have been 

 made, is a matter for future investigation. 



A problem which suggests itself in connection with this novel 

 work will be to determine the limiting change in inclination, 

 which we will assume means rock-bending, that culminates in 

 sudden fracture and a jar, causing an earthquake. 



Earthquake prophets up to the present appear to have lived 

 upon the reputation of a few correct guesses, the nonoccurrence 

 of which would have been contrary to the laws of chance. As ob- 

 servation has shown us that a very large proportion of our earth- 

 quakes, like those which occur in the Himalayas and the Alps, 

 and even those which occur in volcanic Japan, are produced by 

 faulting or sudden breakages in crumpling strata, rather than by 

 explosions at volcanic foci, it would seem that a study of the 

 bending which leads to fracture would be a legitimate method 

 to approach the vexed question of earthquake prediction. 



Another class of movements to which our attention is called 

 are our old acquaintances, the microseismic or tremor storms, 

 which are now defined as long flat waves which give to the 

 surface of our earth a movement not unlike the swell we so often 

 see upon an ocean. Such disturbances are particularly notice- 

 able whenever a district is crossed by a steep barometrical 

 gradient. It is not unlikely that these movements, which are 

 appreciable at considerable depths, have an effect upon the 

 escape of fire-damp at our collieries, that they may influence the 

 accuracy of delicate weighing operations — as, for example, 

 during the determination of standard weights — that they may 

 interfere with gravitational observations, and that they 

 are a neglected source of error in certain classes of astro- 

 nomical work. Our attention is next directed to the bending 

 effect produced in certain districts by the rise and fall of the 

 barometer, certain areas under variations in atmospheric pres- 

 sure behaving as if they were the vacuum chambers of an 

 aneroid. 



Then there are the earthquakes of comparatively restful countries 

 like our own. A large fault, by which mountains are suddenly 

 lowered and va' leys compressed, takes place in a distant country 



