F ^ \ A" "^ . vummxi of jti^wots 



g^^^^^ I toWlfcTUft? LIBRARY 



PKEFACE 



X AM very conscious of the delay which has intervened between the announce- 



ment of the publication of these Tables and their appearance. This delay has 



been chiefly due to two causes. First the great labour necessary, which largely 



fell on those otherwise occupied, and secondly the great expense involved (a) in 



the calculation of the Tables, and (6) in their publication. This matter of expense 



is one which my somewhat urgent correspondents, I venture to think, have entirely 



overlooked. It is perfectly true that only one single Table in this volume has 



been directly paid for, but a very large part of the labour of calculation has been 



done by the Staff of the Biometric Laboratory, whose very existence depends on 



the generous grant made to that laboratory by the Worshipful Company of 



Drapers. Our staff is not a large one and it has many duties, so that the progress 



of calculation has of necessity been slow. Even now I am omitting projected 



Tables, which I can only hope may be incorporated in a later edition of this 



work, e.g. Tables of the Incomplete B- and F-functions, and the Table needed to 



complete Everitt's work on High Values of Tetrachoric r when r lies between 



— -SO and — 1-00. It would only satisfy my ideal of what these Tables should be, 



^ had I been able to throw into one volume with the present special tables, 



Cl extensive tables of squares, of square roots, of reciprocals and of the natural 



1. trigonometric functions tabled to decimals of a degree. Logarithmic tables are 



^ relatively little used by the statistician to-day, which is the age of mechanical 



calculators, and he is perfectly ready to throw aside the fiction that there is any 



v/*' gain in the cumbersome notation of minutes and seconds of angle — a system 



which would have disappeared long ago, but for the appalling ' scrapping ' of 



'j astronomical apparatus it would involve. But the ideal of one handy book for 



p the statistician cannot be realised until we have a body of scientific statisticians 



"^ far more numerous than at present. Statisticians must for the time being carry 



. O about with them not only this volume but a copy of Barlow's Tables, and a 



K< set of Tables of the Trigonometrical Functions. 



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