Nov. 23, 1888. 



SCIENTIFIC NEWS. 



523 



in the forest. These tracts have evidently maintained 

 their boundaries very accurately for a long time, and are 

 surrounded by very ancient trees. They have been 

 formed by Danthonia compressa. The seeds of trees 

 which fell upon the grass were unable to reach the 

 soil, and thus withered away ; but as soon as cattle were 

 turned upon these meadows, and the grass was eaten 

 down, young trees sprang up everywhere ; and though 

 most of them were browsed down by the cattle, some 

 escaped, shot up, and finally overspread the entire 

 meadow. Meehan applies this observation to the great 

 prairies. He considers that the grasses took possession 

 of these regions soon after their elevation above the sea 

 level, and certainly before the seeds of trees could be 

 brought thither and could be developed. The trees 

 advancing laterally found themselves checked by the 

 grass, which hindered their seeds from vegetating, and 

 only permitted them to advance very slowly by suckers 

 from the roots. Since the advent of man they have 

 been further retarded by the prairie-fires. The sandy 

 tracts formed an exception, as upon them the grass grew 

 less luxuriantly, and the seeds of the trees were able to 

 vegetate. Thus in the prairie region we meet the striking 

 phenomenon that the sandy tracts are wooded, whilst 

 richer soils remain covered with grass. 



NEW HEATING APPLIANCES. 



MESSRS. FLETCHER AND CO., of Warrington, 

 have just added two more heating apparatus to the 

 already large variety introduced by them. Fig.i represents 

 an instantaneous water heater which is at once simple and 

 efficient. It can be made only 14 ins. long by 6 ins. 

 high, and can be fixed to a wall as illustrated ; a heater 



Fig. 1. 



of this size will yield one quart of water per minute, 

 heated from 60 degs. to 125 degs. F. It will be seen 

 that a large number of circular flanges are attached to 

 the cylindrical body of the heater, and as these flanges are 

 made of copper, and as jets of gas are burnt under them, 

 they offer a large heating surface and conduct heat 

 rapidly to the water. The heater is strongly made, and 



is not easily injured even if the gas is lighted and the 

 water forgotten. The inlet and outlet tubes at each end 

 of the heater are interchangeable so that they can be 

 fixed on whichever end is most convenient. 



Another useful little apparatus is shown in Fig. 2. 

 This consists of an atmospheric burner, above which 

 there is a movable cylinder, and on this a stand for 



Fig. 2. 



glass flasks, porcelain dishes, flat-bottomed vessels, or a 

 sand bath. By lowering or raising the cylinder the 

 vessel to be heated can be placed at different heights, 

 and by this simple contrivance and by turning on the 

 gas more or less the temperature can be closely regulated. 

 These burners are made in four different sizes. 



THE GREENLAND EXPEDITION. 



T^HE Times, in a letter from a Danish correspondent, 

 gives the following account of Dr. Frithiof Nansen's 

 adventures in his attempt to cross Greenland on snow- 

 shoes : — 



In May Dr. Nansen and party left in the Thyra for Ice- 

 land, via Granton, and on June 4th they embarked in the 

 Norwegian whaler, the Jason, Captain Jacobsen, who had 

 promised to take them to the eastern Greenland coast in 

 Denmark Sound. Circumstances did not prove as 

 favourable as had been expected, and the Jason had to 

 try several places without being able to come near 

 enough to the shore. At last a convenient point was 

 found outside the Srmilik Fjord at about 65 deg. 30 

 min. N. lat., and on July 17th, at 7 p.m., the doctor and 

 his five men, with their well-packed baggage, were 

 landed on the ice rim. From Isafjord, in Iceland, 

 they had brought a little pony, whose assistance 

 they had reckoned upon for drawing their heavy sledges 

 over the first ice and for then supplying them with some 

 fresh meat, but fodder got short on board and the pony 

 had to be killed before leaving. The party had a light 

 boat to help them over open spaces in the water, and 

 their first advance, as seen from the vessel, appeared 

 quite satisfactory. The last that was seen of them was 

 some hours later, when, from a huge ice-block, they 

 waved their adieu and disappeared in the fog. Since 

 then until now nothing has been known of the party, fear 

 and hope struggling for the upper hand. We now learn 



