216 
grown some length, but not finding their tops coming down thiough tne 
surface of the mould, I examined the contents of the tub, and found that 
they had all grown upwards towards the bottom of the tub, and that in 
those whose eyes had been placed downwards the young shoot had turned 
round so as to rise up. As one experiment leads to another, I wished to 
see how a bean would grow if kept in a constant rotatory motion. For this 
purpose I put some earth in a basket, having the shape of a cylinder, and 
about a foot diameter, with the two ends of wood for greater strength, 
through the centre of which I fixed an axis or spindle; in this earth I planted 
a bean, about half way between the surface and axis, with its eye to the sur¬ 
face. The basket was laid across the mouth of a large tub, with the ends 
of the spindle resting on the edges of the tub, which were fitted to one 
another so as to allow of easy motion. Round the basket was rolled some 
small cord, to the end of which was suspended a box, water tight; into this 
was put lead, so as almost to make it sink in water, and which was sufticient 
to turn the basket round in the open air. This large tub was filled with 
water, and the box placed upon it, and the spindle with the basket placed 
across the mouth of the tub; a very small hole was bored at the lower end 
of the tub, which allowed the water to escape, but very slowly; as the water 
sunk in the tub the box descended, and as the box descended the basket 
turned round. This tub took about twelve hours in emptying, and during 
that time the spindle with the basket only turned about once and a half. 
The tub was repeatedly filled, and when I conceived the bean might have 
grown some inches, if it had grown at all, I examined it, and found it had 
grown as much as if it had been planted in the common ground, but it had 
no particular direction but that of passing in a straight line from the bean, 
which was at first towards the circumference, the direction in w r hich it was 
planted; but in its course it had met with a small stone, which had turned 
it into the direction of the axis, and it had gone on in a straight line in that 
direction. Here, as there was no fixed inducement to grow in any one 
^ direction, the bean grew in a straight line in that direction given it by 
chance. 
The ingenious Mr. Knight performed the following experiments to eluci¬ 
date this mysterious subject. 
Having a strong rill of water passing through my garden, I constructed 
a small wheel similar to those used for grinding corn, adapting another 
wheel of a different construction, and formed of very slender pieces of wood, 
