Let us consider, first, Professor Fisher's estimate of M'V', taken together. M'V' is considered to be equal to the total amount (in dollars) of checks deposited during the year.[386] To get this, for 1909, Kinley's figure, above, for checks deposited in 11,492 banks on March 16, 1909, is used. This figure is 647 millions. As half the banks had not reported, an estimate for the non-reporting banks was obtained from Professor Weston, who had aided Dean Kinley in the investigation, and who had access to the original data. Professor Weston estimated the total checks deposited during the day at 1.02 billions.[387] The question then arose as to whether this day was typical for the year. Professor Fisher found New York City bank clearings of March 17 (the day after, on which these checks would get into the clearings) to be 28% below the average for the year. He assumed the rest of the country to be half as abnormal as New York City, and increased the 1.02 billions to 1.20 billions, getting what he conceived to be the daily average of checks deposited in the United States in 1909. Multiplying this figure by 303, the number of banking days in New York City (and so, presumably, a fair average for the number of banking days in the country), he obtained 364 billions for the checks deposited in 1909. This figure he considered to be M'V', the volume of bank deposits,[388] multiplied by its velocity of circulation. To obtain V', therefore, his problem was simple: he divided the figure for M'V' by the figure for M' previously obtained from government statistics, and obtained V'. Now I wish to call attention to three important errors involved in this calculation of M'V' for 1909. (1) The assumption that the total check circulation is the same as the volume of checks actually used in _trade_ is a violent one. _Payments_ may be tax payments, loans and repayments, gifts, what not. Many checks may be used in a single transaction. Surely not all of this is properly to be counted in the M'V' of the equation of exchange. But this topic is better discussed in connection with the estimate for T, and I reserve its fuller discussion till then. (2) The assumption that the rest of the country was abnormal in its clearings on March 17, 1909, is a pure assumption, which investigation does not verify. The rest of the country was, in fact, nearly normal! The error that comes for the year from increasing the total on this assumption amounts to at least 31 billions! The total for the year, on Professor Fisher's method of computation, with the correction to make the assumption regarding outside clearings correspond with the facts, is 333 billions, instead of 364 billions! As the figure for 1909 is a basic figure, on which figures for other years are calculated, this error is extremely significant.[389]