This accords with Dr. Cattel's inquiry of 461 American men of science; in 285 cases it was stated that the family was voluntarily limited, the cause being given as health in 133 cases, expense in 98 cases, and various in 54 cases. Sidney Webb's investigation among "intellectuals" in London showed an even greater proportion of voluntary limitation. The exhaustive investigation of the Galton Laboratory of National Eugenics leaves little room for doubt that in England the decline in the birth-rate began about 1876-78, when the trial of Charles Bradlaugh and the Theosophist leader, Mrs. Annie Besant, on the charge of circulating "neo-Malthusian" literature, focused public attention on the possibility of birth control, and gradually brought a knowledge of the means of contraception within reach of many. In the United States statistics are lacking, but medical men and others in a position to form opinions generally agree that the limitation of births has been steadily increasing for the last few decades; and with the propaganda at present going on, it is pretty sure to increase much more rapidly during the next decade or two. Some instructive results can be drawn, in this connection, from a study of the families of Methodist clergymen in the United States.[126] Although 98 out of every hundred of them marry, and they marry early, the birth-rate is not high. Its distribution is presented in the accompanying graph (Fig. 38). It is evident that they have tended to standardize the two-child family which is so much in evidence among college professors and educated classes generally, all over the world. The presence of a considerable number of large families raises the average number of surviving children of prominent Methodists to 3.12. And in so explaining the cause of the declining birth-rate among native-born Americans, we have also found the principal reason for the _differential_ nature of the decline in the nation at large, which is the feature that alarms the eugenist. The more intelligent and well-to-do part of the population has been able to get and use the needed information, and limit its birth-rate; the poor and ignorant has been less able to do so, and their rate of increase has therefore been more natural in a large percentage of cases. It is not surprising, therefore, that many eugenists should have advocated wider dissemination of the knowledge of means of limiting births, with the idea that if this practice were extended to the lower classes, their birth-rate would decrease just the same as has that of the upper classes, and the alarming differential rate would therefore be abolished. [Illustration: FAMILIES OF PROMINENT METHODISTS