May 17th – Only a short ride today, as my stomach was bad and I was busy with other stuff.

On the canal at Newtown, a familiar scum is developing, and I always get concerned mail from readers about it, who are justifiably concerned that the canal has been polluted by some foreign substance.

Well, it has and it hasn’t: but it’s nothing to worry about. The white film is the pollen and detritus from Sallow trees (Goat Willow) which bloom at this time of year and shed white fluff to the four winds – and it gathers on the canal surface, looking like some terrible contaminant.

It’s really a natural, organic thing and nothing to worry about.