  We present observations of strength one defects and antidefects formed in
isotropic-nematic phase transition in a thin layer of nematic liquid crystals,
using a cross-polarizer setup. We measure the widths of the distributions of
{\it net} winding number in small regions, and determine the exponent
characterizing the correlation between defects and antidefects to be
0.26$\pm$0.11, in very good agreement with the value 1/4 predicted by the
Kibble mechanism for defect production. We also describe a novel technique to
determine the director distribution in observations of defect networks.
