82 NATURAL SCIENCE [August 
and the Shale, lie several seams of so-called coprolites or nodules of 
phosphates of lime. The seams vary in thickness from three inches 
to eighteen inches, and all are formed of these nodules closely com- 
pacted. We have had an opportunity of assisting at an analysis of 
these nodules, from which it was demonstrated that not only are 
they remarkably free from iron, but that they are ten per cent. 
richer than are the imported Belgian samples. It must not be sup- 
posed that these seams are peculiar to Handley’s Pit only—they 
extend uniformly throughout the middle hills of Lincolnshire, and 
are exposed in most of the pits from Lincoln to Grantham. If 
properly exploited the phosphate industry in Lincolnshire might be 
made second only to that of its great iron mines and foundries.” 
HumBer Mup 
THERE is mud in the Humber estuary, mud and sand, and a great 
deal of it. Where does it come from ? 
This is the question that the Hull Scientific and Field Natu- 
ralists’ Club set itself to discuss on April 13th, the discussion being 
opened by its energetic secretary, Mr T. Sheppard. The usual 
reply that the mud comes from the tributary rivers, Ouse, Trent, 
and Hull, is soon found to be inadequate. The mud is accumu- 
lating so rapidly that the material brought down by the rivers is 
insufficient to account for it. Not only sand and mud banks but 
dry land is continually being formed. Reed’s Island, between 
North and South Ferriby, was, some twenty-five years ago, com- 
paratively small, with a plot of grass on which a few cattle were 
reared. Now it is hundreds of acres in extent, has an enormous 
number of cattle grazing upon it, and is still growing. As for the 
accused rivers, their waters are comparatively clear and hold but few 
particles in suspension. Such detritus as they do transport is for 
the most part redeposited on their own banks, or in the alluvial 
flats so characteristic of the Ouse and Trent. It is, however, 
noticed that the water near the mouths of these rivers is far more 
muddy when the tide is flowing up them; and this suggests that 
the mud may be brought into the Humber from the sea. 
The waters of the North Sea are continually washing particles 
of rock, sand, and mud in a southerly direction, and slowly but 
surely the material on the Yorkshire coast is travelling southward. 
It never travels in a northerly direction. As is well known, the 
beach around Flambro Headland is strewn with masses of chalk of 
all sizes, which have been dislodged from the cliffs. These can be 
seen in plenty in Bridlington Bay and further south, though natu- 
rally getting less plentiful as they get Humber-wards. Hardly any 
chalk boulders are found north of the headland. This proves that 
the beach-material travels southward. Now the cliffs of the Holder- 
