The latter entrusted the work of survey to Nazuka Masaiye, with whom was associated the best mathematician of the era, Zejobo, and it is recorded that owing to the minute measures pursued by these surveyors and to the system of taking two-thirds of the produce for the landlord instead of one-half or even less, and owing, finally, to estimating the tan at 300 tsubo instead of at 360 without altering its taxable liability, the official revenue derived from the land throughout the empire showed a total increase of eight million koku, equivalent to about £11,000,000 or $54,000,000.