rudygodinez : 
 
  Carl D. Anderson,  Positive Electron , (1933)  
 The above image is a cloud chamber photograph of the first positive electron (positron) ever observed. 
  The original caption on the photograph reads as follows:  
  A 63 million volt positron (  H    ρ     = 2.1×10   5    gauss-cm) passing through a 6 mm lead plate and emerging as a 23 million volt positron (  H    ρ     = 7.5×10   4    gauss-cm). The length of this latter path is at least ten times greater than the possible length of a proton path of this curvature.  
  First published in the  Physical Review  in March 1933.

rudygodinez:

Carl D. Anderson, Positive Electron, (1933)

The above image is a cloud chamber photograph of the first positive electron (positron) ever observed.

The original caption on the photograph reads as follows:

A 63 million volt positron (Hρ = 2.1×105 gauss-cm) passing through a 6 mm lead plate and emerging as a 23 million volt positron (Hρ = 7.5×104 gauss-cm). The length of this latter path is at least ten times greater than the possible length of a proton path of this curvature.

First published in the Physical Review in March 1933.