NORTON: SPRING FLO^^TERS IN THE FALL 285 



The oxygen is stored over mercury in the glass gas-holder at the 

 right. 



To hold the temperature at 1450°, the furnace requires 580 

 amperes at about 1.8 volts. Its power consumption is therefore 

 no greater than that of an ordinary wire-wound furnace, when 

 the loss of heat in regulating-rheostats in connection with the 

 latter is taken into account. 



The current is supplied to the fm-nace from the secondary 

 of a small 25 : 1 transformer. The primary of the transformer 

 is supplied by a motor generator of 60 cycles and a voltage 

 range from to about 300 volts. The generator voltage is regu- 

 lated by means of its field current, which is supplied by a 110 

 volt storage battery and passes through rheostats alongside the 

 potentiometer. Bj^ regulation of the field current the furnace 

 current can be regulated without any waste of electrical energy, 

 and if the voltage applied to the motor of the motor-generator 

 is reasonably constant, the temperature can be held constant 

 without difficulty to one degree at 1500°. This degree of con- 

 stancy is very often necessary for accurate measurements of the 

 dissociation pressures of hon oxides, as these pressures change 

 quite rapidly with changes of temperature. 



BOTANY. — Spring flowers in the fall. J. B. Norton, Bureau 

 of Plant Industry. 



To the ordinary observer of living things in their natural 

 surroundings the various evidences of evolution have appealed 

 in a more or less remote way as something that happened in the 

 distant past. The modern experimental methods of hj^bridiza- 

 tion and of stud}^ of mutating strains do not appeal with the 

 necessary force to make us reahze that evolution is potent now, 

 as it was in the Carboniferous age. ^^^lile these researches are 

 interesting as showing means of preserving new characters once 

 they originate, the average layman wants to see the actual ap- 

 pearance of a new character. The origin of some characters and 

 their progressive development b^^ gradual accumulation to a 

 point at which the new element is of value to the organism 



