The upper end of the Long Water is now a carpet of algae. Here, a Great Crested Grebe is coping well with the mess and has caught a small fish.

There are a few fish fry to be seen, but not nearly as many as there would be in a normal year. The lake has already had tons of hydrogen peroxide and magic anti-phosphate slurry dumped in it recently, and I fear that these crude mechanical interventions to 'improve the water quality' are actually worsening it.

There was a large dead roach in the Serpentine near the bridge, but this is normal, since these fish are sometimes so battered and exhausted by spawning that they die.

The Moorhens' nest near the Italian Garden has been abandoned again, with one intact egg in it. It was not in a good place -- far too exposed -- but this is unusual. This reed bed has been a successful nest site in past years, and the Moorhens are doing all right elsewhere. Elizabeth has found a brood of seven on the pond of the Sunken Garden at Kensington Palace; here is a link to her charming slideshow of them.

A shy Treecreeper came near enough to be photographed. See how the bird supports itself on the tree by using its long, stiff tail to make a kind of tripod.

The Greylag Geese on the Serpentine have now started moulting their wing feathers, and the lee shore of the lake is full of shed primaries, just asking to be made into quill pens. Here are instructions from no less a person than Gerardus Mercator (1512-94), the inventor of the famous Mercator projection for maps, who was also a calligrapher. You will notice in his diagram that the curve of the quill shows that it is from the left wing, which makes it more comfortable to hold. He writes:

'Choose a transparent, medium-hard quill. I say 'transparent' because, if it is clouded with white marks, it will be less easy to make the correct slit in it. It must be of medium hardness because, if it is too soft, it will supply too much ink, and, if it is too hard, it will usually supply too little; and it will cause other difficulties as well.

'When you are preparing your pen, first make very sure that the slit follows a diameter of the quill; you can do this most easily in the middle of the back of the quill.

'Then see that the point is moderately thin, so that sufficient ink to make individual letters flows gently down. If it is stubby and wide, it will release too much ink for your letters; if it is too long and narrow, then it will release too little. Next cut the extreme tip back a little from the edge which faces away from you as you write, but in such a way that the whole of the edge so cut is in contact with the paper when the pen is being used. See too that the slit you made before is in the centre of this writing edge, thus ...'

A translation of the captions in the diagram:
Bona fissio: good (vertical) cut
Mala fissio: bad cut
Linea resectionis: line of trim
Planicies payri: surface of paper
Bona cuspidis resectio: good trimming of the tip
Extrema aciei mala abscissio, fissio item per inequalia resectionis lineam dividit: a bad trimming of the extreme point, the cut divides the line of the trim into unequal parts.