October 9, 1885.] 



SCIENCE. 



319 



Since 1881 a new aspect of affairs has appeared 

 through the wine industry. The culture of the 

 vine, after some partial failures on account of lack 

 of experience with the different climatic and other 

 conditions, is now an undoubted success ; and it 

 comes just at a time when the vine-growers m the 

 south of France are beginning to despair of con- 

 quering the insect pests wliich are destroying their 

 vines. Accordingly, large numbers of them have 

 emigTated, and then* capital and good-will have 

 given a large impetus to the French colonization of 

 Algeria. It is also found that the ohve flourishes 

 exceedingly well, and the prospect for the financial 

 success of the colony is at last brighter. The gov- 

 ernment has spent, from first to last, an enormous 

 sum of money upon Algeria ; the railways, roads 

 and other conveniences for travelling are in better 

 condition than in Italy; and with the present good 

 outlook in wine, oil and grain growing, it appears 

 as if Algeria were to have an important future. 

 Whether France will ever reap the result of her 

 efforts there, or some other nation step in in her 

 place, or even an independent state arise there, 

 time alone will teU. 



RECENT GRAVITY DETERMINATIONS IN 

 AND NEAR JAPAN. 



In the year 1880 Professor Mendenhall, then 

 professor of physics in the University of Tokio, 

 made a determination of the force of gravity at 

 that place, using a 'Borda's pendulum,' and 

 comparing its measuring-rod with a meter, in the 

 possession of the Japanese treasury department, 

 which was a certified copy of the standard at the 

 Conservatoire des arts et metiers. The determi- 

 nation was thus an absolute one, and, from the 

 circumstances under which it was made, it would 

 seem probable that the resulting value of g, 

 9.7984m, must be very near the truth. This is 

 very sHghtly in excess of the values given by the 

 formulae generally accepted as best representing 

 g for any latitude, as deduced from a large num- 

 ber of determinations on different parts of the 

 globe. 



Since 1880 several of Professor Mendenhall's 

 pupils, in the department of physics (notably Mr. 

 Tanakadate, now assistant to the professor of 

 physics), have made determinations of g at four 

 places in and near Japan, swinging two or three 

 * invariable ' pendulums, in each case first at 

 Tokio, then at the station in question, and again 

 at Tokio, and they furnish very accurate relative 

 values of the force of gravity at all these places. 

 The results have been published in a series of three 

 appendices to No. 5 of the Memoirs of the science 



department of ToJcio daigaku, which contained 

 Professor MendenhaU's work. 



The most recent one is of unusual interest, for 

 in it is the result of a determination of g at the 

 Bonin islands, which he out in the Pacific five or 

 six hundred miles south-east of the coast of Japan, 

 and which have for a haK-century been of note 

 among geodesists, as the place where the force of 

 gravity is most in excess of the normal value of 

 any thus far observed. 



In the years 1826-9 Captain Leutke, in com- 

 mand of a Russian expedition, visited these islands 

 and determined the value of g to be about 0.0025m 

 larger than the normal value, which will be, per- 

 haps, better appreciated by saying that it indicated 

 that a seconds-pendulum would vibrate there about 

 11 sec. per day faster than at the same latitude in 

 most parts of the earth. This value has always 

 been considered as abnormal, and generally left 

 out in any discussion of the figure of the earth 

 from gravity determinations. The interest at- 

 taching to the last determination by Mr. Tanaka- 

 date lies in the fact that, if Professor Mendenhall's 

 value of g for Tokio is nearly correct, then at 

 present it is even more in excess at the Bonin 

 islands than deduced by Captain Leutke ; the last 

 result giving about 0.0034m over the normal value 

 of g, or a gain 15 sec. per day in a seconds-pen- 

 dulum. 



The whole result of the measurements on this 

 part of the globe, thus far pubhshed, is best shown 

 in the following table, which shows the date, 

 place, latitude, observers, and the correction which 

 the observations give to the value of g, as deduced 

 from the mean of Everett's, Listing's and Herschel's 

 formulae which are closely accordant. In the final 

 column is the corresponding gain in seconds per 

 day, of a pendulum, which, with the nonnal value 

 of g given by the formulae, would vibrate 86,400 

 times per day at each place. 



Place. 



Ogasawarajima, 

 Bonin Islands. 

 Tokio, Nippon. 



Sapporo, Yesso. 



Kagoshima, 

 Klu-shiu. 



Naha, 



Liu-biu Islands. 



Ogasawarajima, 



Bonin Islands. 



Lati- 

 tude. 



+27 4 

 +3541 



+43 4 



+3125 



+2612 

 +27 4 



Observers. 



Leutke 



Mendenhall 

 ( Tanakadate ) 

 •< Fujisawa V 

 / and Tanaka ) 



Tanakadate) 

 Sakai and V 



Yamaguchi ) 

 I Tanakadate 1 

 •^ Sakai and > 

 ( Yamaguchi \ 

 ( Tanakadate | 

 ) and Sawai i 



Excess of 

 gravity. 



+0.0025 

 +0.0003 



+0.C00' 



+0.0007 



+0.0010 

 +0.0034 



see. 

 +10.9 

 + 1.3 



+ 3.1 

 + 3.1 



4.4 



+14.9 



Mr. Edwin Smith, of the coast sui'vey, and Pro- 

 fessor H. S. Pritchett, of the Washington univer- 



