Section IIL, 1908. [ ISB ] Tbans. R. S. C. 



XII. — A Note on the Zamboni Pile. 



By A. S. Eve, D.Sc, McGill University, Montreal. 

 (Communicated by Prof. H. T. Barnes, D.Sc, and read May 28th, 1908.) 



The Zamboni Dry Pile consists of many layers of paper disks, 

 with zinc foil on one side and binoxide of manganese on the other. 

 The internal resistance is enormous ; the E. M. F. notoriously incon- 

 stant. A dry pile of this sort has kept an electric bell, consisting of 

 a small ball oscillating between brass hemispheres, ringing for more 

 than fifty years. On the other hand, Professor Rutherford tried to 

 use these piles at Montreal for charging electroscopes, but found them 

 in a few months quite inefficient. I recently procured three piles from 

 Germany, and found their E. M. F. to range from 270-330 volts, 

 respectively. These were effectively used last autumn for charging 

 wires out-of-doors to collect the active deposits, Ra C and ThC, from 

 the atmosphere. 



In February I resumed work with them, and found that they 

 gave no E. M. F. whatever. I put one under the water tap, and 

 steamed another for an hour before the spout of a boiling kettle. 

 These drastic measures produced a slight improvement which did not 

 last. 



In April, when a marked thaw and a south wind arrived, and the 

 furnaces of the building were allowed to go out, the piles entirely 

 recovered the full E. M. F. of the previous autumn. 



The variability is doubtless due to the dry Canadian winter 

 removing all moisture from the paper disks until the resistance 

 approaches infinity. The dry pile becomes too dry. 



The Zamboni piles should therefore be kept in closed vessels, with 

 some damp substance, such as a moist sponge, present. 



It is possible that the pile could be adapted, with an electro- 

 scope or voltmeter, to form a sensitive hygrometer. 



