Abstract
The assembly of a spray apparatus consisting of 169 hypodermic needles is described. This apparatus could give a concentrated flow of spray at a wide range of drop sizes and rates of flow. In the range of drop size 0.6-2.4 mm the drop size uniformity of the spray was much better than could be obtained by pressure nozzles. Coalescence of the drops while falling, however, was a factor which decreased the uniformity as compared with drops falling from a single needle.