?16 (3) Owing to the fact that the influx of people into Bombay is not constant from year to year the census may show a population either greatly in excess of the average yearly dry weather population or greatly below it The 1901 census population was supposed to be much below the normal the 1906 census was certainly greatly in excess of the normal. 38. Census population and actual population.-The census of 1906 was taken on February 9th at a time when the population of Bombay was swollen by an influx of destitute famine refugees and an army of worker in excess of the number usually finding employment there, and it was recognized at the time that an abnormal influx of people had occurred. The Administration Report of the City for 1906-1907 speaks of the deficient rainfall of 1905 and remarks- "As usual, the influx of famine refugees proved to be one of the "principal causes of the increased unhealthiness of the City......". Many important works also were undergoing construction during this year and served to attract an abnormal number of labourers to the City. The Executive Health Officer records in his report for 1906 that- "Electric tram-lines are under construction which has brought to "the City a large number of labouring hands, to add to the number already "engaged in the construction of the Docks. A large number of labourers "is also employed for the construction of the Harbour Railway of the "Port Trust. In this way there is a floating population of about 50,000 in "addition to the standing population." A specially large number of women was present in the City that year, as shown by the increase in the total female deaths, which rose 3,000 in excess of the mean of the previous four years. The total number of registered births also reached the highest figure ever recorded. The number of mill-hands resident in the City had also shown an increase. The average daily number of mill-hands employed in Cotton Mills since 1901 is as follows:- 1901 ... ... 82,162 1902 ... ... 86,122 1903 ... ... 96,913 1904 ... ... 89,915 1905 ... ... 92,924 1906 ... ... 100,798 1907 ... ... 98,101 1908 ... ... 101,536 39. All these facts point to the presence of a specially large population in 1906; but there are grave reasons for doubting the accuracy of the special census held in that year. In 1901 the census, which was carried out in March, showed a ratio of females to males of 617, and the death returns during the months of January, February and March 1901 show a ratio of female deaths to male of 590, 598 and 604 rising to 691 in April. It is apparent therefore that there was a close relationship between the proportion of females to males as ascertained by the census and that inferred from the relative mortality of the two sexes about the census period. But the 1906 census, which was carried out in February, gave a ratio of only 595 females to 1,000 males, though the mortality returns show that in January, February and March respectively, 802, 737 and 712 females died to every 1,000 males. This lack of correspondence between, the ratio of female to male deaths and that of living females to living males, as found by the census, indicates a serious error in the enumeration. If we assume that the female population was accurately enumerated, there appears to be a discrepancy in the number of males, the total of 612,965 found by the census being at least 100,000 in excess of the number actually present in the City. Such an error might easily occur by failure on the part of the enumerators to cancel names of absentees at the final enumeration, 40. Fortunately there are means which enable us to find out whether the mean population of the City varies to the extent the census figures show.