Page:The Construction of the Wonderful Canon of Logarithms.djvu/105

NOTES ON TRIGONOMETRICAL PROPOSITIONS. 81 whether there be given two angles with the interjacent side or two sides with the contained angle. In each oe the important point is what occupies the third place in the proportion, In the former it is the tangent of half the base, in the latter the tangent of the complement of half the vertical angle. In these examples, if the tangent or the sum of the sines be greater than radius, the logarithm is negative and has a dash preceding, for example &minus;8328403.

Another way of the same ]

Then divide the sum of the first and second found by the square of radius, and you will have

To make the sense clearer, I should prefer to write this as follows:—

Then divide both the first and second found by the square of radius, add the quotients, and you will have the tangent, &c.