726 The Trials of Self -hmding Harvesters at Chester. 
fro to suit tlie crop, by means of a lever under the driver’s 
control. 
The sheaf-carrier consists of an upper curved two-prong fork 
projecting from a wooden rocking-shaft hinged to the frame 
which carries the binding machinery ; and of a lower part com- 
posed of six prongs, which are hinged to a hollow bar attached 
by brackets to the main frame of the machine, some 7 in. 
below the lower edge of the binder platform, and a little to the 
outside of it. Each prong is pivoted into a small rocking-lever 
and rests also in a guide. The outer ends of the rocking-levers 
are connected by a bar, which in its turn is connected by rods 
and cranks with a double foot-lever secured to the driver’s 
footboard just in front of his seat. One lever raises the prongs 
and the other lowers them, but so that where they are lowered they 
are free to trail along the ground and so avoid catching in ir- 
regularities. 
The whole of the details of this machine are thoroughly sub- 
stantial and well made. 
W. Anderson. 
WATER IN RELATION TO HEALTH 
AND DISEASE. 
Introduction 
The world’s stock of water exists in our seas and rivers on 
the one hand, and in the earth and air on the other. Its 
physical state is constantly undergoing change, — at one time 
it permeates the atmosphere as invisible vapour, and at another 
condenses into visible clouds, soon to assume the liquid state 
and fall to the earth as rain. 
• Reaching the ground in this form it either passes into the 
soil or over it — in the one case to emerge again in the course of 
springs, in the other to enter more directly into our rivers, and 
finally to reach the sea. Under the influence of heat it is again 
dissipated in vapour from land and sea, rising upward and 
falling anew as rain, or snow, or hail, or mist. In this way it 
maintains a constant circulation between earth and air — in the 
one suffering various degrees of organic and inorganic contami- 
nation, in the other reaching its highest form of natural purity. 
The purest of natural water is supplied in the form of rain, but 
even in this state it cannot be said to be altogether free from 
