A data set from Oehlert (2000) \emph{A First Course in Design and
Analysis of Experiments}, New York: W. H. Freeman.

Data originally from Shoemaker, A.~C., K.-L. Tsui, and C.~F.~J. Wu (1991).
``Economical experimentation methods for robust design.'' 
{\em Technometrics\/}~{\em 33}, 415--427.

Columns are A, B, C, D, E, F, G, H, and thickness of silicon.