But whether belonging to our system or far beyond it, the great nebula must have enormous dimensions.  A vast gaseous system it is, sustained by what arrangements or forces we cannot tell, nor can we know what purposes it subserves.  Mr. Huggins’ discovery that comets have gaseous nuclei, (so far as the two he has yet examined show) may suggest the speculation that in the Orion nebula we see a vast system of comets travelling in extensive orbits around nuclear stars, and so slowly as to exhibit for long intervals of time an unchanged figure.  “But of such speculations” we may say with Sir J. Herschel “there is no end.”

To return to our telescopic observations:—­The trapezium affords a useful test for the light-gathering power of the telescope.  Large instruments exhibit nine stars.  But our observer may be well satisfied with his instrument and his eye-sight if he can see five with a 3-1/2-inch aperture.[3] A good 3-inch glass shows four distinctly.  But with smaller apertures only three are visible.

The whole neighbourhood of the great nebula will well repay research.  The observer may sweep over it carefully on any dark night with profit.  Above the nebula is the star-cluster 362 H. The star [iota] (double as shown in Plate 3) below the nebula is involved in a strong nebulosity.  And in searching over this region we meet with delicate double, triple, and multiple stars, which make the survey interesting with almost any power that may be applied.

Above the nebula is the star [sigma], a multiple star.  To an observer with a good 3-1/2-inch glass [sigma] appears as an octuple star.  It is well seen, however, as a fine multiple star with a smaller aperture.  Some of the stars of this group appear to be variable.

The star [rho] Orionis is an unequal, easy double, the components being separated by nearly seven seconds.  The primary is orange, the smaller star smalt-blue (see Plate 3).

The middle star of the belt ([epsilon]) has a distant blue companion.  This star, like [iota], is nebulous.  In fact, the whole region within the triangle formed by stars [gamma], [kappa] and [beta] is full of nebulous double and multiple stars, whose aggregation in this region I do not consider wholly accidental.

We have not explored half the wealth of Orion, but leave much for future observation.  We must turn, however, to other constellations.

Below Orion is Lepus, the Hare, a small constellation containing some remarkable doubles.  Among these we may note [xi], a white star with a scarlet companion; [gamma], a yellow and garnet double; and [iota], a double star, white and pale violet, with a distant red companion.  The star [kappa] Leporis is a rather close double, white with a small green companion.  The intensely red star R Leporis (a variable) will be found in the position indicated in the map.

Still keeping within the boundary of our map, we may next turn to the fine cluster 2 H (vii.) in Monoceros.  This cluster is visible to the naked eye, and will be easily found.  The nebula 2 H (iv.) is a remarkable one with a powerful telescope.