The gifts of nature. 

 - s.l.:    Ontario Hydro,    1979. 
 - 49 p. :    ill. ;    21 cm. 
<br/><br/><label>Subjects--Topical Terms: </label><br/> Electricity.
<br/><br/><label>Gov. Doc. Class. No.: </label>G.CAN/O.H (02)1979/1