  In 1989, the Whipple 10m telescope achieved the first indisputable detection
of a TeV gamma-ray source, the Crab Nebula. Until its decommissioning in 2011,
the Whipple telescope took regular measurements of the nebula. With the recent
discovery of GeV gamma-ray flaring activity in the Crab Nebula, it is an
opportune time to return to the Whipple telescope data set and search its
extensive archive for evidence of TeV flares. A data set on the Crab Nebula
spanning ten years, 2000 - 2010, is compiled and searched for day-scale flaring
activity using a Bayesian-block binning algorithm. No evidence for significant
flaring activity is found. Monte Carlo simulations show that low levels of flux
increase on short timescales are difficult to detect. Assuming a flare duration
of seven days, 99% confidence level upper limits are calculated for the
possible frequency of five-fold, two-fold and 1.5-fold flares in the data set.
An upper limit of 0.02 flares per year is found for the five-fold flare, and a
limit of 0.27 flares per year is placed on the two-fold flare. The detection of
the 1.5-fold flare is consistent with the false-positive rate of the method,
and so cannot be excluded.
