36 Bolam: The Natural History of Hornsea Mere. 
spring, whenever possible. When it is in that condition 
there is no great chance of the Mere becoming flooded to any 
appreciable or harmful extent, as it has then a natural overflow 
in full working order. Should the water fall, however, during 
the latter part of April, or May, say more than a couple of inches. 
below the top of the sluices (the outflow having then, of 
course, ceased) great care should be exercised to ensure that, 
as far as possible, no further rise be permitted, say before the 
end of June; to avoid this either one or both gates being 
opened as far as necessary in the event of heavy rain coming. 
If careful attention was paid to this point, the rise, or fall, 
of the water could thus be controlled to the extent of the height 
of the sluice-gates—17 inches—which should, in any average 
year, be anample margin. Of course it assumes two important 
conditions ; first that the April level of the Mere can be got 
up to the 17 inch level, and secondly that there is a reasonable 
chance of maintaining it for a month or two somewhere between 
that point and the bottom of the gates—17 inches lower. 
Should the water, despite all precautions, fall below that point, 
of course it gets out of control, and all that can then be done is 
to set the gates open and keep them so during the remainder 
of the nesting season, ready to allow a free overflow as soon 
as the water rises up to them. 
In this way any serious summer flood could be made 
reasonably unlikely, if it could not be altogether prevented. 
Had it been followed this year it would have prevented the 
unfortunate drowning of nests which took place in May. 
Of serious human poaching on the Mere I am glad to be 
able to report that there was this year practically none. The 
local people understand pretty well that the place is preserved 
and looked after, and from the holiday crowds not much 
inconvenience was experienced. Along with Taylor, I, of course, 
took special precautions on big holiday days, and all those 
who were trespassing, and had to be turned back, took it in 
good part and went quietly away. Most of them probably 
came in ignorance, or through carelessness in not having read 
the printed instructions posted up in Holmes’ Boat House and 
in the boats. Some of them, more disposed to wit than their 
fellows, assured me that they ‘ were not naturalists but only 
harmless holiday-makers’ ! Few or no eggs were taken, I think, 
except those of some common bush- and hedge-building birds, 
which fell in the way of children, and the latter we never had 
much difficulty in keeping under control. 
There is, however, one very bad poacher at Wassand to 
whom a line or two may be devoted, although I am afraid 
that naturalists and birds alike must agree to put up with 
his constant presence and lay their plans accordingly. He 
has been known since the time of Linnaeus as Camis vulpes. 
Naturalist,. 
