INTERMITTENT MIXERS.
67
Proper measure of gravel for a charge, whilst the bags contain the proper
quantity of cement, and a cistern near at hand (filled by a flexible hose)
the proper quantity of water. Two men standing on the waggon (the
sides of which are generally raised so that it contains about twice the
quantity of an ordinary earth waggon) are able to fill the hopper in the
»ne employed by four men to give the mixer the requisite number of
uins. For counting these a tell-tale is provided, which indicates when the
Fig. 29. —Messent Concrète Mixer.
Piopei number of turns is completed; the mixer is then stopped with the
f 11 .°'vnwaids- The door fastening is released and the charge of concrete
s into its place, the discharge being instantaneous. The opening of the
th ^en linned upwards, as in the figure, the door is opened (through
ov6 - arc as ^own^ tJie hopper, suspended from the davit, is brought
th ■ 6 °Pen’n8 and at once discharged into it, and the water is run in from
cistein at the same time. The door, which closes water-tight, is then