In Cygnus, at R.A. 20^h 41^m 7^s, Dec. +30° 19′, near κ and especially in the region immediately north-east, there exist irregular and extensive streams of faint nebulosity which may be said to form a telescopic milky way, Nebulæ and stars are curiously grouped together, forming a remarkable arrangement which will well repay study. To see these objects satisfactorily, a moonless night, free from haze or fog, should be chosen, and the power should be moderately low, or some of the more feeble nebulous films will be lost. The observer may spend some agreeable hours in sweeping over this region, which is one of the best in a wonderfully rich constellation. _Further Observations._—The fact that Swift has discovered many hundreds of nebulæ during the last few years affords indubitable proof that considerable numbers of these objects still await detection. No doubt they are generally small and faint, but it is necessary they should be observed and catalogued, so that our knowledge in this department may be rendered as complete as possible. New nebulæ are sometimes mistaken for expected comets, and occasionally give rise to misconceptions which would be altogether avoided were our data more exhaustive. Those who sweep for nebulæ must have the means of determining positions, and a small telescope will be inadequate to the work involved. A reflector of at least 10 inches, or refractor of 8 inches, will be required; and a still larger instrument is desirable, for to cope successfully with objects of this faint character needs considerable grasp of light. The power employed should be moderate; it must be high enough to reveal a very small nebula, but not so high as to obliterate a large, diffused, and faint nebula. In forming his first catalogue of 1000 nebulæ, Sir W. Herschel used a Newtonian reflector of 18·7 inches aperture, power 157, field 15′ 14″; Swift’s recent discoveries were effected with a 16-inch refractor and a periscopic positive eyepiece, power 132, field 33′. With a low power a very extensive field will be obtained, and a large part of the sky may soon be examined, but it will be done ineffectively. It is better to use a moderately high power, and thoroughly sweep a small region. The work is somewhat different to comet-seeking; it must proceed more slowly and requires greater caution, for every field has to be attentively and steadily scanned. If the telescope is kept in motion, a faint nebula will pass unseen. Some of these objects are so feeble that they are only to be glimpsed by averted vision. When the eye is directed, say, to the E. side, a faint momentary glow comes from the W. side of the field; but the observer discerns nothing on looking directly for the object. On again diverting his gaze he receives another impression of faint nebulosity from the same point as before, and becomes conscious of its reality. Frequently, while comet-seeking, I meet with a small indefinite object, the character of which cannot be determined by