"Fellow workers," Nancy began again, and this time there was only respectful silence, "I have come to you today to tell you a little something about the machines which are forever your property, which were given to you by your Maker and which it is your sacred duty to keep in as good condition as possible. I mean your own bodies." She paused, and Tom nodded encouragement from the other room. "It has become my pleasant duty to come to you and tell you how you may keep these God-given machines. You are to regard me, in other words, as your friend and sister." The lecturer was here threatened by a dry, pippy, cough and the whole course was imperilled. However, she drove fiercely on. "At the outset you should have a brief working knowledge of such things as your heart and lungs, your pancreas, liver, big and little intestines and their juices; and I shall, accordingly, give you a brief idea of the various systems, beginning today with the circulatory and respiratory. Next time I shall hope to cover the digestive and excretory tracts, and I shall close with two talks on personal hygiene." This ended the preliminary matter, and the lecturer proceeded with the body of her talk in a somewhat more mechanical style. The respiratory system was dismissed in six minutes, although, in some curious way, Mr. Sprig had strung the same material out to half an hour. Before beginning upon the circulatory system, however, she sprang a surprise. "For your convenience," she explained, "I shall draw a diagram of the heart and its valves, and with your assistance I shall explain its action." After a little wrestling with the diagram, which _would_ curl, she managed to pin it to the wall. She then proceeded, in red crayon, to draw a fully equipped heart. She finished with audible relief and, turning triumphantly--greeted Miss Balch and her brother Leofwin. "Dear me, I am afraid we are intruding," said Miss Balch, looking around with ingenuous charm. Henry, having heard the bell which the social workers had been too absorbed to hear, appeared at the door and relieved the situation temporarily. Leofwin, however, whose eye was naturally caught by the pictorial, was gazing at the circulatory system on the wall. "What on earth is that?" he asked, with more curiosity than was perhaps excusable. "It looks for all the world like some sort of impressionistic valentine." Nancy, for one reckless moment, was tempted to say that it was, but temperate judgment prevailed. After all, why need she be ashamed of what they were doing? "Tom and I are giving a course of lectures at the Mill, in hygiene, and we are just rehearsing a little; that's all. The valentine shows the heart action. Those arm things are the valves, you see." "But, really, you know, even a valve must have some perspective." "Well, of course, I'm no artist. The cut in the dictionary was very small, and when I enlarged it I tried to get the right proportions, but I just had my tape measure and----"