Thesaurarium mathematicae, or, The treasury of mathematicks containing variety of usefull practices in arithmetick, geometry, trigonometry, astronomy, geography, navigation and surveying ... to which is annexed a table of 10000 logarithms, log-sines, and log-tangents / by John Taylor.

PROP. XXXV. By knowing the Moon's Place in the Ecliptick, (having little or no Latitude) and her Paral∣lax of Altitude, to find the Parallaxes of her Longitude and Latitude.

First, If the Moon be in the 90° of the Eclip∣tick, she hath then no Parallax of Longitude, and the Parallax of the Latitude, is the very Parallax in that Altitude.

Secondly, But if the Moon be not in the 90th. Degree of the Ecliptick, to find the Parallaxes of the Latitude and Longitude, the Analogy or Proportion is,

1. As Radius or S. 90°,

To T. of the V. of the Ecliptick and Horizon,

So is Sc. of the Moon's Distance from the As∣cendent, or Descendent deg. of the Ecliptick,

To Tc. of the Ecliptick's V, with the Azimuth of the Moon.

AGAIN say,

2. As the Radius or S. 90°,

To S. of that V. found,

So is the Parallax of the Moon's Altitude,

To the Parallax of her Latitude sought.

LASTLY say,

3. As the Radius or S. 90°, 00'

To Sc. of the former V. found,

So is the Parallax of the Moon's Altitude,

To the Parallax of his Longitude sought, which being added to the true Motion of the Moon, if she be on the East part of the 90° of the Eclip∣tick. Or from it to be deducted if she be on the West part of the 90° of the Ecliptick.