the Rev. Professor Pritchard

“ A general notion of the effects of precession on the positions of the stars may be seen at once by observing the three positions of the Pleiades, at the three epochs B.C. 2300, A.D. 1, and A.D. 1878, marked in the chart by the letters K, L, M; and as the approximate effect of precession is to cause all stars to move parallel to the Ecliptic and through the same arc, if the reader will imagine every star to be shifted parallel to the Ecliptic through spaces equal respectively to K L, L M, he will get the aspect of the heavens at the epochs A.D. 1 and A.D. 1878. ”

“ Again, if it be required to find what constellation is culminating at the time of sunset at the Summer Solstice, the cardboard must be moved, as before, towards the right hand until the position of the Sun at the Summer Solstice, viz. G, just touches the horizon curve, when it will be seen that α Serpentis and Antares are then culminating, Regulus and β Centauri are just setting, while the constellations of Aquila and Aquarius are rising; Vega is a conspicuous object above the eastern horizon. ”