The articles that were cited earlier, have now gone into the National Post archive (where you have to pay to read them). However, the pdf for the English version of the Dutch article in Natuurwetenschap & Techniek (which is virtually identical to the National Post version) is at Ross McKitrick’s site at this link .
Here’s a choice quote from the article that caused me to fall from my chair (my emphasis in bold):
"McIntyre and McKitrick went back to the source of the Gaspé series and then to the archived data at the World Data Center for Paleoclimatology. "We found that although the Gaspé series begins in 1404, up until 1421, it is based on only one tree. Dendrochronologists (tree ring researchers) generally do not use data based on one or two trees. The original authors only used this series from the 1600s onwards in their own temperature reconstructions. This series should never have been used for the 15th Century, let alone counted twice and extrapolated"
I check with Steve McIntyre – yes, it’s true. I then find out that from 1421 to the 1450s, there were only two trees involved…