NA TURE 



[Decembek 21, 1905 



meter, the time occupied in passing from the upper to the 

 lower well being thus found, and giving the rate of flow 

 of the water. 



Further details of observations of underground flow as 

 carried out by this method are given in paper No. 112, by 

 Homer Hamlin, with numerous illustrations of the 

 apparatus used. 



Stove-pipe Wells. — In the same report is a paper by 

 Charles S. Slichter on the method of sinking stove- 

 pipe wells. These consist of a riveted sheet steel starter 

 hum 15 feet to 25 feet long, made of two or three thick- 

 nesses of sheet steel with a forged steel shoe at the lower 

 end. The rest of the casing consists of two thicknesses 

 of sheet steel made into riveted lengths of 2 feet, one set 

 of sections being made just so much smaller than the 

 other as to permit them to telescope together. Each outside 

 section overlaps the inside section 1 foot. This casing 

 is sunk, length by length, by hydraulic jacks, which press 

 on the upper sections by means of a suitable head. Alter 

 the well has been sunk to the required depth, a rutting 

 knife is lowered into the well and vertical slits are cut 

 in the casing opposite such water-bearing strata as may 

 have been met with ; a well 500 feet deep may have 400 

 feet of screen if circumstances justify it. The perforator 

 is handled with 3-inch pipe. By raising slowly on the 

 line with hydraulic jacks, cuts are made from three-eighths 

 to three-fourths of an inch wide, and from 6 to 12 inches 

 long. 



The well casings vary in diameter from 17 inches to 

 14 inches, and are sunk to depths from 500 feet to 1400 feet, 

 the yield of water varying from 300,000 to 3,000,000 gallons 

 in twenty-four hours. The cost of a 12-inch 300 feet 

 well is about 140Z. for labour and 100/. for materials, the 

 drillers being paid ll. and the labourers 10s. a day. The 

 soil where these wells are in use consists of mountain 

 debris, clay, gravel, sand, and boulder. 



Pollution of Streams by Waste from Factories. — Paper 

 No. 103 contains a review of the laws in operation in the 

 different States of America for the prevention of pollution 

 of inland waters. The broad legal principles under which 

 anti-pollution statutes become operative are explained, and 

 important Court decisions are quoted to show the authority 

 upon which certain deductions in the report are founded. 



In paper No. 133 the special stream pollution arising 

 from the refuse water from the " straw board " factories 

 is dealt with. In Indiana, Ohio, and Illinois there are 

 several large factories engaged in making pasteboard 

 from rye, wheat, and oat straw. For this process 40,000 

 gallons of water are required to wash 1 ton of straw, and 

 3200 lb. of straw and 560 lb. of lime are required to 

 make 2000 lb. of board. In an ordinary factory 2,000,000 

 gallons of water are used daily, which carries with it 

 10 tons of straw waste and 10 tons of lime. This waste 

 generally runs into a neighbouring stream, and is the 

 cause of a serious amount of pollution. The report of 

 the Government Commissioner for Fisheries states that 

 the pollution of the streams in Indiana by the refuse from 

 the strawboard mills, oil mills, and pulp mills is greater 

 than from any other source. The refuse from these covers 

 the spawning beds and prevents the eggs from hatching, 

 while it penetrates the gills of the living fish and either 

 kills or drives them away from the streams. 



The remedy is by chemical precipitation of the waste 

 products, but it is contended that the small profit on the 

 manufacture of strawboard does not permit of the appli- 

 cation of the process required. 



Another source of water pollution dealt with in this 

 report arises from the overflow from the oil wells in 

 Indiana. Around the city of Marion there are no less 

 than seventy-five oil wells in a few square miles of terri- 

 tory. Upwards of 300 surface and rock wells in this 

 area are suffering contamination from this source. The 

 strata in this district consists of sand and gravel for 

 about 50 feet, then clay for about 80 feet, and below this 

 limestone. The water supply of the town and neighbour- 

 hood is derived from water in the limestone, and there is 

 a constant flow of underground water. Oil occurs near 

 the top of the formation." Beneath the oil is salt water. 

 In order to form a reservoir for the oil the limestone is 

 entered some distance, and the most successful wells are 

 those which are drilh .1 deep enough to allow a large 

 N >. 1886, VOL. 73] 



amount of oil to collect, so as to be above the upper level 

 of the brine. These oil wells are generally 1000 feet deep, 

 the oil rising to within 600 feet or 700 feet of the surface. 

 When the well is bored it is " shot " with nitroglycerin, 

 which breaks up the limestone and forms fissures and 

 small cavities which act as reservoirs into which the oil 

 flows. Thi- surface effect of the shooting is the violent 

 ejection of salt water and oil, often to the extent of 

 thousands of gallons. The oil and salt water then sink 

 into the soil where it is porous, and finally reach the 

 surface zone of underground flow, where they partake of 

 the general movement of the water toward tiie main line 

 of underground drainage, and cause its pollution. The 

 brine and oil pumped from these oil wells is discharged 

 into a settling tank. The oil, owing to its lighter specific 

 gravity, settles at the top and is drawn off, the brine 

 being discharged into any neighbouring creek or stream, 

 or is allowed to sink slowly into the ground, in either case 

 becoming a serious source of pollution to the water supply 

 of the neighbourhood. 



Paper No. 121 relates to the pollution of Lake 

 Champlain, by M. O. Leighton. The report was made in 

 consequence of complaints made to the Government that 

 the water of the lake has been rendered unfit for domestic 

 consumption ; that the usefulness of the lake for watering 

 cattle has been destroyed ; and that the refuse poured into 

 it is destructive to fish life. The cause of pollution is due 

 to the waste discharged into it from the pulp mills situated 

 on its banks. The analysis of the water and other details 

 are interesting to those who have to deal with the making 

 of pulp and similar industries. 



Paper No. 122 is entitled " Relation of the Law to 

 Underground Waters," by D. W. Johnson, and contains 

 an outline of the main features of the laws respecting 

 underground waters with the object of giving to the owner 

 of such waters some idea of his rights and obligations 

 concerning them. Such legal decisions as serve to show 

 the relation of the law to the problems which are essentially 

 geological in character are referred to. Underground 

 waters are defined and classified. Although this paper 

 refers to United States practice, there is a great deal of 

 information that would be of service to water engineers in 

 this country. We shall refer more fully to this paper in 

 a future number. 



THE PERCY SLADEN EXPEDITIOX IN 



11. M.S. "SEALARK" TO THE INDIAN 



OCEAN. 



[" HAVE just received the following interesting com- 



■*• munication from Mr. Stanley Gardiner. It was written 



from Port Victoria, Seychelles, under date October 28, and 



is tlie fourth report of his expedition which he has sent 



home. Mr. Gardiner is expected home early in the New 



Year. For his earlier reports, see Nature, August io, 



October 5, and November 9. A. SEDGWICK. 



Cambridge, December 1. 



During the ten days that the Sealark left us at Coetivy 

 while she was coaling in the Seychelles, we as thoroughly 

 as possible collected the animals and plants of both the 

 land and reef. The island was higher than any we had 

 up to that time visited, having wind-blown sand ridges 

 and hills up to 80 feet above sea-level, arising on a flat 

 coral reef. Although situated only about 130 miles to the 

 south of the Seychelles Islands, the land fauna and flora 

 are almost the same as on the islands of the Chagos Archi- 

 pelago, being scarcely richer in either. The plants, of 

 course, in the main necessarily govern the fauna, and it 

 would appear to us that they are in their turn governed 

 rather by the nature of the soil — coral and coral sand — 

 than by their proximity to continental land. On the other 

 hand, the reefs of Coetivy showed in every group of 

 marine animals a more varied fauna than those oi the 

 Chagos, while very nearly all the species of the latter 

 seemed to be present. The reef on the eastern, or sea- 

 ward, face of the island was of a rather different character 

 from any we had as yet seen (or from any I have seen in 

 the Pacific), being covered with 1 grass-like weed, locally 

 termed " varech." There was also on the same part a. 



