# Popular and Mathematical Astronomy, with the principal formulę of Plane and Spherical Trigonometry, for the use of schools

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Page 41 - Aries (the Ram), Taurus (the Bull) Gemini (the Twins), Cancer (the Crab), Leo (the Lion), Virgo (the Virgin), Libra (the Scales), Scorpio (the Scorpion), Sagittarius (the Archer), Capricornus (the Goat), Aquarius (the Water-bearer), and Pisces (the Fishes).
Page 72 - TO THEIR DIFFERENCE ; So IS THE TANGENT OF HALF THE SUM OF THE OPPOSITE ANGLES', To THE TANGENT OF HALF THEIR DIFFERENCE.
Page 124 - ... instrument is out of adjustment in this respect, the direct and reflected images will not coincide, but the reflected image, as the arm moves, will be slightly above or below the direct image. Adjust the horizon-glass so that the two images coincide when the reflected passes the direct in moving the arm. 3. To make the axis of the telescope parallel to the plane of the arc. Prepare two blocks which are equal in height and the same as the height of the center of the telescope above the plane of...
Page 61 - A sin(A + B) = sin A cos B + cos A sin B cos(A + B) = cos A cos B - sin A sin B...
Page 88 - The law of sines states that in any spherical triangle the sines of the sides are proportional to the sines of their opposite angles: sin a _ sin b __ sin c _ sin A sin B sin C...
Page 87 - B . sin c = sin b . sin C cos a = cos b . cos c + sin b . sin c cos b = cos a . cos c + sin a . sin c cos A cos B cos c = cos a . cos b + sin a . sin b . cos C ..2), cotg b . sin c = cos G.
Page 91 - When a ray of light passes from a rarer to a denser medium, it is bent towards the perpendicular, at the point at which it entered.
Page 75 - The sphere may be conceived to be generated by the revolution of a semicircle DAE (fig.
Page 64 - The sines of the sides of a spherical triangle are to each other as the sines of the opposite angles. Let abc (fig.
Page 54 - When you have proved that the three angles of every triangle are equal to two right angles...