PROFESSIONAL ADVANCEMENT COLUMN 



This column serves as a place in which it is possible for men to insert brief notices 

 with a view to securing positions or securing men, either in botany or any of its related 

 and applied branches. The identity of advertisers may be learned from the Editor of the 

 Plant World. Notices should not exceed 100 words. They will be inserted once for 50 

 cents, three insertions for $1.00. 



THE PLANT WORLD 



Tucson, Arizona 



LARGE AUTO-IRRIGATORS 



For the automatic watering of large pots or beds of soil we offer an Auto- 

 Irrigator Cup which is similar to the ordinary Atmometer in its form and 

 proportions, but is 14 inches in length and U inches in diameter. These 

 large cups are installed and operated in the same manner as the smaller 

 Auto-Irrigators which are now in general use, and also lend themselves 

 to various other purposes. Each .80, per ten $7.00. 



Directions for the use of Auto-Irrigators will be sent on request. 



THE PLANT WORLD - - Tucson, Arizona 



DATATTXTr' TADTT? for equalizing the exposure 



J\UlAlli>VJ 1 AD L<ri OF A SERIES OF PLANTS V? ^ 



This becomes an indispensable de- 

 vice in every physiological laboratory 

 after its first trial. It is impossible to 

 give equal conditions to all plants in a 

 standing series of cultures. For the 

 proper standardization of Atmometer 

 Cups it has been found absolutely nec- 

 essary. The table-top is circular, 4 feet 

 * in diameter, of 5-ply wood, and is 

 mounted on a bicycle wheel, which is 

 supported on a heavy iron tripod base. 

 It is rotated by. a belt from a reducing 

 gear, which is operated by a 1/20 H. P. electric motor or other sources of 

 power . A hot-air engine or small gas engine would also serve. A good speed 

 of rotation for most purposes is from 1/5 to 5 revolutions per minute. See Plant 

 World 15: 157-162, 1912; Physiological Researches 1: 345- 1915. 



WEIGHT READY FOR SHIPMENT, ABOUT ISO LBS. 



Price of Rotating Table Complete, $30.00 



Table Top Alone, $7.50; Tripod Base Alone, $8.50 



THE PLANT WORLD TUCSON, ARIZONA 



