372 
MR. J. W. L. GLAISHER’S NUMERICAL VALUES OF THE 
The maxima and minima values of the sine-integral correspond to multiples of r. 
Those above 4tt were calculated by formulae (2), the others were deduced by Taylor’s 
theorem from other values, Si r from Si 3 and Si 3T ; Si 2 tt from Si 6 ; Si St from Si 9; 
and Si 4 t from Si 13. 
The cosine-integral has its maxima and minima values for odd multiples of \<x. Those 
above -§ ir were calculated from formulae (2), the others were deduced from previously 
calculated values, Ci from Ci 1*6 ; Ci -§t from Ci 4*7 ; Ci -fx from Ci 8; Ci f-sr from 
Cill; and Ci f t from Ci 14. The difference formulae in the form best adapted for 
logarithmic computation are : 
Si (x-\-h) — Si x 
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+ 
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