1 1 8 Mifcellanea Curio fa, 



greater than i bp, otherwife — ) the Sum, 

 when | bb is greater than p>> the difference 

 when lefs. And in the other Formula, the 

 Root is always compos'd of the fame parts, 

 only the Sines and — - being varied, as 

 they will eafily perceive that are willing to 

 make the Tryals. 



But thefe Roots are readily enough found 

 fey the help of the Log. Table of verfed Sines \ 

 viz. if the Coefficients are fyrd or broken 

 Numbers, and the Roots not to be expreffed 

 in Numbers, as raoft commonly it happens. 



Now this is the Rule. In the firft and fe- 

 cond Formula, if f bb be lefs than />, let j p 

 — r | bb •zz dj and putting the difference be- 

 tween % bp; and f 7 bl i<% g (that is H R) in 

 the firft Formula, and the difference between 

 § bp i " i 9 and \ 7 fa (in the fecond Formula). 

 Radius, let the Angle, whofe Tangent is 



be found. Then, as the Co- fine of this 

 Angle, to the virfiA Sine of the fame, fq 

 the Difference made Radius, to a fourth Quan- 

 tity, the Cube Root of which will be had by 

 taking the f of its Log. Then dividing f p — 

 i bb by this Cube Root, let the Divifor be 

 fubftracted from the Quotient, the Remainder 

 will be the Quantity Y& at Fig. i . The Sum of 

 this Remainder and \b will be the Root, 

 fought, if the Center - falls on the Right 

 Hand of the Axis ; otherwife their Difference 

 will he the Root. But if f bb be greater 



than />, making H R Radius, let d\f d (or 

 the diftance" of the Paraboloid from the 

 Axis) be the Sine of fome Arch*,.' let the 



verfed 



