countries, except Austro-Hungary and Germany, have had more _marriages_, in the twenty years from 1861 to 1880, not only these, but Holland, Spain, and Italy, have had more _births_, and all of them except Denmark, Norway, and Sweden have had more _deaths_, in proportion to their numbers.[400] One great advantage of the census is, that it enables the registrars to calculate from their own data, with certain sure limits of told-out numbers behind and before them. “When the registers contain all the births and deaths, and there are the means [given by the census] of setting out from a known population, it is obviously the same as an actual enumeration.”[401] Malthus suggested in 1803 that the experiment of 1801 should be repeated every ten years, and that registrars’ reports should be made every year.[402] This has been done; and, if both have been accurate, then the registers of the intervening years, on the basis of the decennial enumeration, ought to make us able to calculate the numbers for any intervening year. Accordingly, the population of England in 1881, as calculated from the births and deaths, was little more than one-sixth of a million different from the numbers as actually counted over on the night of the 4th of April in that year.[403] The growth in the last decade, 1871 to 1881, was higher than in any since 1831–41;[404] the births were more and the deaths fewer than usual. Another London has been added to our numbers in ten years.[405] This gives no sure ground, however, for prediction. To suppose a country’s rate of increase permanent is hardly less fallacious than to suppose an invariable order of births and deaths over the world generally. Even if we are beyond the time when we need to make any allowance for increasing accuracy and fulness, and if we may assume that no given census has any units to sweep into its net that through their fear or an official’s carelessness escaped its predecessor, still we cannot take the rate of increase from one census to another as a sure indication of the future. With some qualifications the words of Malthus apply to us in 1881 quite as accurately as to our fathers in 1811: “This is a rate of increase which in the nature of things cannot be permanent. It has been occasioned by the stimulus of a greatly increased demand for labour, combined with a greatly increased power of production, both in agriculture and manufactures. These are the two elements which form the most effective encouragement to a rapid increase of population. What has taken place is a striking illustration of the principle of population, and a proof that, in spite of great towns, manufacturing occupations, and the gradually acquired habits of an opulent and luxuriant people, if the resources of a country will admit of a rapid increase, and if these resources are so advantageously distributed as to occasion a constantly increasing demand for labour, the population will not fail to keep pace