A data set from Oehlert (2000) \emph{A First Course in Design and Analysis of Experiments}, New York: W. H. Freeman. Data originally from Bergman, B. and A.~Hyn\'{e}n (1997). ``Dispersion effects from unreplicated designs in the $2^{k-p}$ series.'' {\em Technometrics\/}~{\em 39}, 191--198. Variances for data in pr18.5