304 THE FRUIT GARDEN 



intervals, otherwise the whole may get choked with lime. The water pumped 

 up from the chalk in the eastern and southern English counties should be 

 carefully guarded against. 



With reference to the working of the hot-water heating apparatus, where 

 there are several circulations at various levels there is often great difficulty in 

 preventing blocking or short circuiting, and while a good deal can be done 

 to avoid this trouble by carefully fixing the pipes, it is necessary that the valves 

 regulating each circulation should be manipulated in a careful and intelligent 

 manner. Those circulations nearest the boiler or on a higher level should be 

 carefully watched to ascertain the amount of restriction necessary to give 

 the longer and more sluggish circulations an equal chance. It is quite im- 

 possible to formulate any rule which would apply in all circumstances, and the 

 attendant should be encouraged to study the apparatus from day to day until, by 

 experience, he learns what degree of restriction each valve must be set to. 



