In the ruling of paper it should be practical to run several hundred pens continuously for hours, all of the pens carrying the appropriate amount of ink, which amounts to as much as 0.4 ml per minute per pen. Not only must the flow be adequate regardless of the speed of the paper‐feed within the limits of the machine but the flow of ink must practically stop with the stoppage of the machine. These requirements are met in an elegant manner by the use of capillary siphons, the most important part of which consists of woolen threads or “worsteds” which in themselves are very flimsy affairs, being made of very loosely twisted fibres but around these threads the capillary action forms a liquid skin which serves as the walls or the ink‐delivery tubes, offering comparatively little resistance to flow.