238 



SCIENCE 



[N. a Vol. LI. No. 1314 



tensively worked as early as 1871. None were 

 recorded in Costa Rica, however, until 1915, 

 when American engineers found deposits in 

 western Costo Rica and, under the stimulus 

 of the prevailing high prices, explored many 

 of them. During 1916, 1917, and 1918 about 

 18,000 tons of ore was exported from Costa 

 Rica to the United States. In October, 1918, 

 the Geological Survey, taking advantage of 

 the presence in Costa Rica of an American 

 geologist, J. D. Sears, had the deposits ex- 

 amined. Dr. Sears afterward visited several 

 new deposits in Panama. 



The dejxjsits in Costa Rica are foimd at 

 several places on the Nieoyan peninsula, in 

 the Province of Guanacaste, which extends 

 along the Pacific coast. Most of the known 

 deposits, and all those which have been the 

 source of the shipments, lie within about 16 

 miles of Playa Real on the Pacific coast in 

 the northern part of the peninsula. Other 

 isolated deposits occur in the eastern part of 

 the peninsula, near the Gulf of Nicoya. As 

 the central part of the peninsula is covered 

 with dense forest and is difficult to cross, 

 further exploration may bring other deposits 

 to light. 



Although deposits of manganese oxides 

 were examined at thirty-six places near Playa 

 Real, most of the ore shipped has been derived 

 from three deposits that lie in an area 

 scarcely 1,000 feet square at Playa Real. 

 These deposits are owned by the Costa Rica 

 Manganese & Mining Co., and American com- 

 pany. At Playa Real, as at many other places 

 in the region, the manganese oxides form very 

 irregular masses, which appear to extend 

 along the crests of hills. The genesis of the 

 deposits is obscure, but sufficient work has 

 been done to show that only a few persist for 

 as much as 100 feet below the surface. Esti- 

 mates of the size of the known deposits, 

 which, however, are based upon very inade- 

 quate data and are therefore probably low, 

 indicate that they might yield 10,000 to 15,- 

 000 tons in addition to the 18,000 tons already 

 shipped. The oxides are intimately mixed 

 with silica, so that careful sorting is nec- 

 essary to produce material containing more 



than 45 per cent, of manganese. After the 

 oxides are sorted they are carried by lighters 

 to ships anchored near the shore. 



The deposits in Panama lie in an inac- 

 cessible region along Boqueron River, about 

 20 miles northeast of Colon. They are about 

 12 miles southwest of the deposits at Nombre 

 de Dios, which were extensively explored from 

 1871 to 1902. These deposits are poorly ex- 

 posed and only a few of them have been ex- 

 plored, but the indications in two small areas 

 warrant an estimate that the deposits there 

 may yield 25,000 to' 30,000 tons of high-grade 

 oxides. As there is considerable float along 

 the near-by streams other deposits may be 

 found. In order to export the material, how- 

 ever, roads or tramways must be constructed 

 at considerable expense. 



THE CAMBRIDGE NATURAL SCIENCE CLUB' 



The Cambridge !N"atural Science Club, 

 founded in 1872, celebrated its 1,000th meet- 

 ing by a dinner in the combination room of 

 St. John's College, Cambridge, on Saturday, 

 January 24. The president, Mr. J. M. Wordie, 

 was in the chair. There were eighty-three 

 members and guests, and the occasion was 

 taken to bring out a complete list of the mem- 

 bers of the club since its inauguration. This 

 shows that of the 330 memlbers 52 are dead, 

 10 having been killed or died on active service 

 during the war, and that 55, or 16.7 per cent., 

 had received the blue ribbon of science — the 

 F.R.S. Indeed, in returning thanks for the 

 guests, Sir J. J. Thomson, who, although 

 president of the Royal Society and master of 

 Trinity, had never been a member of the club, 

 thought that the proportion of fellowships of 

 the Royal Society was probably higher among 

 members of the dub than among fellows of 

 colleges elected on account of their attain- 

 ments in natural science. He confessed that 

 he had never taken the l^atural Science Tri- 

 pos, though he had often examined others for 

 it, and pleaded in defence that, like Professor 

 W. H. Bragg, also a guest, he had made soone 

 vicarious amends by submitting a son to the 

 ordeal. It may be noted that Professor W. H. 



1 From the British Medical Journal. 



