March 26, 1886.] 



SCIENCE. 



277 



survey especially requires that economic work 

 should be done, and as the primary function of 

 the survey is the performance of such work, it is 

 evident that this class of investigation has been 

 carried on strictly in obedience to the law, and in 

 fulfilment of its purpose. 



The annual output of the mines of the United 

 States aggregates in value about $425,000,000 ; 

 and, while the economic results of the survey have 

 largely been devoted to this industry, the needs of 

 the agricultural community have not been forgot- 

 ten. At present investigations are going on of 

 the flood-plain valleys of the great rivers, like that 

 of the Mississippi, for the purpose of determining 

 the conditions under which they can be redeemed ; 

 and, on the other hand, of the great arid regions, 

 to determine by what means they may be more 

 economically fertilized by irrigation ; and, again, 

 of the coast marshes and interior swamps, to learn 

 the possibility of their utilization by drainage. 

 In the prosecution of its topographical work, the 

 survey is constructing a map of the forests of the 

 country ; and in its study of the structural geology 

 it is revealing the conditions under which artesian 

 wells may be discovered, and prognosticating the 

 areas where such wells may be constructed. In 

 the study of the interior hydrography of the 

 country, the survey is developing the conditions 

 under which our towns may obtain a supply of 

 healthful water ; and, in this connection, the calls 

 upon the survey for information are many and 

 rapidly multiplying. It is hardly necessary to 

 add, that, in the construction of a topographic 

 map of the United States, the people are supplied 

 with a knowledge of the natural routes for the 

 highways of commerce. It will thus be seen that 

 the work of the survey has practical relations with 

 all the industries of the people, and that it is pre- 

 eminently designed to promote their welfare. 



THE RAILWAY TO CENTRAL ASIA. 

 Under the direction of General Annenkoff, the 

 Transcaspian railway has made remarkable prog- 

 ress. At the beginning of the present year it 

 extended from Mikhailovsk, on the bay of the 

 same name, to Ghiaurs, a small station some 

 miles beyond Askabad. From thence to Merv 

 the road-bed is finished, and the stations and 

 bridges are constructing. It is expected that 

 trains will run to Merv this spring, and that by 

 midsummer the road will be completed to the 

 Amu Daria at Charjui, a total distance of one 

 thousand and forty-one kilometres. The harbor 

 at Mikhailovsk is very shallow, and the deep water 

 at Krasnovodsk is too distant ; but another spot 

 has been found, twenty-four kilometres from 



Mikhailovsk, where, by a moderate amount of 

 dredging, the largest vessels of the Caspian can 

 come up to a jetty now building. For the other 

 end of the line, to connect with the railway, 

 steamers of a special type are being constructed, 

 suited to cope with the swift and shallow waters 

 of the Amu Daria. The difficulty presented 

 by drifting sands in the desert is to be met by 

 introducing plants, already tested for such pur- 

 poses in the arid regions of Algeria ; and at the 

 principal stations large quantities of them are 

 already being set out in propagating-houses. 



This enterprise is a military road, built and 

 designed by officers of the war ministry, assisted 

 by soldiers, Tartars from the Caucasus, and 

 Turkomans and other inhabitants of the region. 

 The chief difficulty has not been the sands of the 

 desert, but the want of water ; the existing wells 

 being far apart, brackish, and hardly sufficient 

 for the ordinary purposes of the caravans. How- 

 ever, it has been determined by experiment, that, 

 at a certain depth in the soil, w T ater exists in 

 sufficient quantity, and increases at greater 

 depths. Artesian w^ells will therefore be dug, 

 the machinery for which is already on the ground. 

 The worst part of the line determined upon is the 

 desert which extends some two hundred kilo- 

 metres eastward from the Merv oasis. This, 

 though arid and sandy, produces a growth, some- 

 times almost a wood, of the 'saxaul' (Haloxylon 

 ammodendron) and other nearty related shrubs, 

 which only disappear at a distance of some forty 

 kilometres from the Amu Daria. 



After passing the lesser desert near Mikhailovsk, 

 and reaching the station at Kizil Arvat, the rail- 

 way takes a direction parallel to the Kopeth 

 range, which coincides with the borders of Persia. 

 It crosses the Akhal oasis, and passes under the 

 walls of Geok Tepe a few yards from the spot 

 where the assault was made by which the fortress 

 was carried. The most important station is Ask- 

 abad, a nourishing town only three years old, 

 but already enjoying an important commerce 

 with North Khorassan. Farther on, the line 

 passes the Persian village of Lutfabad at a dis- 

 tance of two kilometres, and enters the Attek 

 oasis, now beginning to revive under the security 

 afforded by Russian rule. Duchak, at 391 kilo- 

 metres from Kizil Arvat, is the most southern 

 point of the line, from which diverge the routes to 

 Seraks, Heshed, and Herat. Here the road turns 

 toward Merv, and enters the desert in a north- 

 westerly direction. There are no brooks or 

 springs, but from the mountains to the south-east 

 come two rivers of importance, — the Tajand or 

 Hari-Rud, and the Murghab. The former is dry 

 in winter, but in summer has twice the volume 



