NA rURE 



{_Nov. I, 1883 



provided with an iron shoe or cutting ring, and sinks 

 downwards at first in virtue of its own weight, being 

 lengthened at the top as in the previous case, but after a 

 time it generally becomes necessary to force it down by 

 the [jressure of screws, assisted by the blows of an instru- 

 ment resembling a pile-driver. When it cannot lie made 

 to sink deeper, another similar cylinder of smaller diame- 

 ter is introduced into its interior, the same series of 

 operations are again gone through, and so on untd the 

 solid ground is reached. 



Simple as the last described process may appear, its 

 application is sometimes attended with difficulties of 

 almost incredible magnitude. As an example we may 

 mention two shafts which were sunk through about 400 

 feet of the kind of ground in question at the Colliery 

 Rheinpreussen, near Ruhrort in Germany. One, begun 

 in 1857, was not finished after more than eighteen years' 

 constant perseverance; while the other, begun in Febru- 

 ary, 1867, was only completed down to the solid ground 

 in June, 1872. 



The new method invented by Herr Poetsch is described 

 by BergassessorG. \\.o\\\Qx'\n'i}m Bcrnuiul Hiittotmiiiinische 

 Zi-ilinig, No. 38, xlii. Ja/irqano, September 21, 1883. It 

 consists in freezing the water contained in that portion of 

 the running ground Avhich occupies the position of the 

 intended shaft into a solid mass of ice, and then sinking 

 through it by hand without having to pump any water. 

 To this end a preliminary shaft of larger dimensions than 

 the intended shaft is sunk down to the natural level of the 

 water. A number of vertical bore-holes about one metre 

 apart arc then put down round about its sides at the 

 bottom, so that they pass through the ground just outside 

 the lining of the intended shaft. Others are put down 

 within the area of the intended shaft, and one is put down 

 in its centre. All of these bores are continued down to 

 the bottom of the running ground. They are made by 

 means of the sand-pump, and are lined with sheet-iron 

 tubes in the usual way. A circular distributing pipe with 

 small cojjpcr tubes branching from it is placed at the 

 bottom of the preliminary shaft. One copper tube ex- 

 tends to the bottom of each bore-hole, and each tube is 

 proi'ided with a stopcock. At the surface are several ice- 

 making machines of the Carre type. The liquid intended 

 to circulate through the bore-holes and effect the operation 

 of freezing consists of a solution of the chlorides of mag- 

 nesium and calcium, wdiose freezing-point lies ijetween 

 - 35° C. and — 40^ C. By means of a small force-pump 

 it is made to circulate at such a rate that it leaves the 

 cooling-trough vvith a temperature of about — 25° C. It 

 descends into the distributing pipe, passes through the 

 copper tubes to the bottom of the bore-holes, ascends out- 

 side the copper tubes to the top of the bore-holes, finds its 

 way into a collecting-tube, reascends to the surface, 

 passes through the cooling-trough, and then commences 

 the downward journey again. 



Herr Poetsch estimates that, under ordinary conditions 

 — that is, when the outer ring of bore-holes can be made 

 in the ground outside the lining of the intended shaft — 

 the freezing process will occupy from ten to fourteen days. 



When it has been ascertained by means of bore-holes 

 that the wall of ice round about the intended shaft is 

 thick enough, the operation of sinking is commenced. 

 The ice is cut out by hand, and a descending cylinder 

 of masonry or iron is carried down at the same time. 

 The lining prevents the surrounding ice-wall from break- 

 ing inwards, and the bottom cannot burst upwards. 



Herr Kohler made a personal inspection of this process 

 at the shaft Archibald now being sunk to the lignite beds 

 at Schneidlingen, in Germany. The shaft passes through 

 a bed of running sand four metres thick. Twenty-three 

 bore-holes were employed in two rows near its sides. 

 The freezing process was completed on August 10 last, 

 when the running sand had become a compact mass of 

 such great hardness that no impression could be made on 



it by the finger-nail, and it was with considerable diffi- 

 culty that a flake 15 mm. thick could be broken from it. 



Sufficient data do not yet e.xist for estimating the cost 

 of this process as compared with those already known, 

 but we arc of opinion that if the operation of freezing can 

 be eftected in two or three weeks, or even months, it will 

 compare favourably with them in this respect under 

 almost any circumstances. We belies'e also that it is 

 capable of application under a variety of circumstances 

 not mentioned in Herr Kohler's article, such as damming 

 back an excessive flow of water in solid ground, driving 

 horizontal drifts or tunnels through mud and sand, and 

 so on. We would therefore recommend the inventor 

 rather to turn his attention in this direction than to think 

 of condensing the intake air of mines by the application 

 of cold, with the view of dispensing with ventilating fur- 

 naces and enabling winding operations to be carried on 

 in upcast as well as in downcast shafts. The former 

 field, if we mistake not, will be a large one ; the latter, 

 we can safely promise him, will be a very small one. 



William G.^llowav 



A'OKDENSKJOLD'S GREENLAND 

 EXPEDITION 



IN a series of letters to Mr. Oscar Dickson, Baron 

 Nordenskjold has given a detailed report of the lead- 

 ing incidents and results of his recent expedition, though 

 it will still be some time ere we can learn what are the 

 t'uU gains to science. The leading novelty of the expe- 

 dition was, of course, the journey into the interior of 

 Greenland. We have already given some account of Dr. 

 Nathorst's visit to the Cape York region, and in the 

 present article will confine ourselves mainly to Nor- 

 denskjold's own journey up the interior. We reproduce a 

 sketch map of this journey, which Mr. Dickson has been 

 good enough to send us. After mentioning his attempt 

 to approach the south-east coast of Greenland, Nor- 

 denskjold says : — 



The ice much I'esembled the big rough blocks which 

 are encountered north of Spitzbcrgen. The surface here 

 carries a cold current which sets the ice on shore. The 

 polar current is however not very voluminous ; thus 

 in a depth of a couple of fathoms Herr Hamberg dis- 

 covered, through careful survey, a decided warm current 

 from the south. The depth of the sea was not great, and 

 the bottom consisted of large blocks which tore the trawl- 

 ing net and prevented dredging. 



After landing Dr. Nathorst and his party at Waigatz 

 Sound, Nordenskjold went back to Egedesminde, which 

 he reached on June 29. He then proceeds : — 



The following day I left for Auleitsivik Fjord, from which 

 my expedition was to start. This fjord is about 130 kilo- 

 metres long, and very narrow in the middle, not unlike a 

 river, which widens at the bottom into a bay, Tessiusar- 

 soak, into which an arm of the inland ice shoots. This 

 remarkable formation, and the great tides which favour 

 this part of Greenland, make the navigation here very 

 difficult. As in most of the Greenland fjords the sea is 

 deep and free from reefs. A remarkable feature, too, is 

 that icebergs coming athwart the narrows in the fjord 

 cause the water in the bay suddenly to rise some ten to 

 twenty feet. The Esquimaux relate that some years ago 

 a boat with men, women, and dogs w^as drawn under here 

 by the whirl currents. They are, in consequence, afraid 

 of rowing in the narrows. 



In 1870 I had paid a visit to this fjord and examined 

 these difficulties, which I believed would have increased 

 rather than otherwise during the last thirteen years, 

 through those changes which so often occur in the position 

 and size of the moving glaciers which shoot down from 

 the inland ice. On inquiry I was told that no European 

 had been in the fjord since 1870. Still my knowledge of 



