Fortunately the gathering of vital statistics is not beyond the power of the kind of health officer that is found in small cities and in rural communities. If years of study of mathematics and of the statistical method were required, we should despair of obtaining light within a century. But the facts we want are, for the most part, common, everyday facts, easily recognizable even by laymen; for example, births, deaths, age at death, causes of death, cases of transmissible diseases, conditions found upon examination of children applying for work certificates, etc. Where expert skill is required, as at state and national headquarters, it can be found. Every layman can train himself to use skillfully the seven ingredients of the statistical method which it is his duty to employ, and to know when to pay for expert analysis and advice. We can all learn to base judgment of health needs upon the seven pillars,--desire to know, unit of inquiry, count, comparison, percentages, classification, and summary. FOOTNOTES: [7] Dr. Arthur Newsholme's _Vital Statistics_ should be in public libraries and on the shelves of health officers, public-spirited physicians, and school superintendents. CHAPTER XIV IS YOUR SCHOOL MANUFACTURING PHYSICAL DEFECTS? Last year a conference on the physical welfare of school children was told by a woman principal: "Of course we need physicians to examine our children and to teach the parents, but many of us principals believe that our school curriculum and our school environment manufacture more physical defects in a month than all your physicians and nurses will correct in a year." At the same meeting the physical director of schools of New York City appealed eloquently for "biological engineers" at school, who would test the child's strength as building engineers are employed to test the strength of beams and foundations.[8] As explanation for the need of the then recently organized National School Hygiene Association, he elaborated the proposition that school requirements and school environment damage child health. "Ocular defects are in direct ratio to the length of time the pupil has attended school.... A desk that is too high may easily be the indirect agent for causing scoliosis, producing myopia or astigmatism.... Physically examine school children by all means, but do not fail to examine school desks." Fifty schools in different parts of New York City were examined last year with especial reference to the factors likely to cause or to aggravate physical defects.[9] The results, tabulated and analyzed, prove that the woman principal was right; many schools are so built or so conducted, many school courses are so devised or so executed, that children are inevitably injured by the environment in which the compulsory education law forces them to spend their formative years. [Illustration: ONE OF NEW YORK CITY'S ROOF PLAYGROUNDS]