Page:Philosophical Transactions - Volume 037.djvu/53

 Hæc de hujus doctrinæ fontibus indigitasse, non abs re fore judicatum est, ne, lectoribus inexercitatis, auctoris nimia brevitas impedimento esset.

In circumferentia circuli (Tab. 2. Fig. 1.) centro quovis O intervallo O R = a descripta applicetur chorda R T = b, cui parallelus ducatur radius O P, ita quidem ut arcus P R sit quadrante major si habeatur + b, minor vero si habeatur − b. Incipiendo in puncto R, sumantur ordine tot arcus $$\text{R} \overset{\text{I}}{\text{R}}, \overset{\text{I}}{\text{R}} \overset{\text{II}}{\text{R}}, \overset{\text{II}}{\text{R}} \overset{\text{III}}{\text{R}}, \overset{\text{III}}{\text{R}} \overset{\text{IV}}{\text{R}}, \overset{\text{IV}}{\text{R}} \overset{\text{V}}{\text{R}},$$, &c. arcui P R æquales, quot unitates continet fractio $$\frac{r}{n}$$, & a punctis $$\overset{\text{I}}{\text{R}}, \overset{\text{II}}{\text{R}}, \overset{\text{III}}{\text{R}}, \overset{\text{IV}}{\text{R}}, \overset{\text{V}}{\text{R}},$$ &c. ducantur totidem rectæ $$\overset{\text{I}}{\text{R}}_\overset{\text{I}}{\text{r}}, \overset{\text{II}}{\text{R}}_\overset{\text{II}}{\text{r}}, \overset{\text{III}}{\text{R}}_\overset{\text{III}}{\text{r}}, \overset{\text{IV}}{\text{R}}_\overset{\text{IV}}{\text{r}}, \overset{\text{V}}{\text{R}}_\overset{\text{V}}{\text{r}},$$, &c. radio O P parallelæ & rectæ O R occurrentes in punctis, $$\overset{\text{I}}{\text{r}}, \overset{\text{II}}{\text{r}}, \overset{\text{III}}{\text{r}}, \overset{\text{IV}}{\text{r}}, \overset{\text{V}}{\text{r}},$$, &c. Deinde dividatur arcus P R in tot partes æquales quot sunt unitates in numero n, quarem illa quæ puncto P