372 EXPERIMENTS WITH FERTILISERS [chap. 



and ground lime in particular, are unpleasant and even 

 dangerous to sow by hand. There are a number of 

 different types of machine on the market, and all will 

 do good work with unmixed dry fertilisers, though some 

 fail to do so with mixed manures. With a mixture 

 containing superphosphate, or still more so dissolved 

 bones, any machine which possesses moving parts 

 working in the manure will be sure to cause the forma- 

 tion of a paste which eventually clogs up the machine 

 and puts it out of action. Whenever a farmer expects 

 to sow mixtures, he must be careful to get a machine 

 of which no part in contact with the manure is actively 

 moving. 



At the Rothamsted experiment station a machine 

 made by Coultas, of Grantham, has been in regular use 

 for some time, and answers admirably. The principle 

 upon which the machine works will be gathered from 

 the diagrams. Fig. 6, which show a section through 

 the box n,Z ft. or lo ft. 6 ins. long, which contains the 

 manure. The manure is thrown over the lip of n by 

 the revolving spindle m, running the whole length of 

 the box, and furnished with a series of radial arms 

 which dip in the manure and toss it over the lip. As 

 the machine travels the bottom and side o of the 

 manure box lift, being driven by the rack and pinion 

 k and /, which are geared to the wheels of the machine *. 

 the side n of the box, however, remains stationary. 

 The spindle is also geared to the wheels of the machine, ■ 

 and the rate at which it revolves, and therefore the rate 

 at which manure is delivered, can be varied by changing 

 the gear wheels. After it is tipped over the lip of «, 

 the manure falls through a closed channel and can be 

 delivered only a few inches from the ground, so as to 

 avoid blowing. It will thus be seen that this machine 

 fulfils the great desideratum of havmg no parts working 



