292 THE POPULAR SCIENCE MONTHLY. 



ence of any such cloud of volatilized iron as that which helps 

 to envelop the sun. 



For another test of what the three-inch will do turn to ^, the 

 lower, or left-hand, star in the Belt. This is a triple, the magni- 

 tudes being second, sixth, and tenth. The sixth-magnitude star is 

 about 2'5" from the primary, p. 149, and has a very peculiar 

 color, hard to describe. It requires careful focusing to get a 

 satisfactory view of this star with a three-inch telescope. Use 

 magnifying powers up to two hundred and fifty diameters. 

 With our four-inch the star is much easier, and the five-inch 

 shows it readily with a power of one hundred. The tenth-magni- 

 tude companion is distant 56", p. 8, and may be glimpsed with 

 the three-inch. Upon the whole, we shall find that we get more 

 pleasing views of i Orionis with the four-inch glass. 



Just to the left of C, and in the same field of view with a very 

 low power, is a remarkable nebula bearing the catalogue number 

 1237. We must use our five-inch on this with a low power, but 

 with i out of the field in order to avoid its glare. The nebula is 

 exceedingly faint, and we can be satisfied if we see it simply as a 

 hazy spot, although with much larger telescopes it has appeared 

 at least half a degree broad. Tempel saw several centers of con- 

 densation in it, and traced three or four broad nebulous streams, 

 one of which decidedly suggested spiral motion. 



The upper star in the Belt, 8, is double ; distance, 53", p. 360 ; 

 magnitudes, second and seventh very nearly ; colors, white and 

 green or blue. This, of course, is an easy object for the three- 

 inch with a low magnifying power. It would be useless to look 

 for the two fainter companions of 8, discovered by Burnham, even 

 with our five-inch glass. But we shall probably need the five- 

 inch for our next attempt, and it will be well to put on a high 

 power, say three hundred diameters. The star to be examined is 

 the little brilliant dangling below the right-hand end of the Belt, 

 toward Rigel. It appears on the map as -q. Spare no pains in 

 getting an accurate focus, for here is something worth looking 

 at, and unless you have a trained eye you will not easily see it. 

 The star is double, magnitudes third and sixth, and the distance 

 from center to center barely exceeds 1", p. 87. A little tremu- 

 lousness of the atmosphere for a moment conceals the smaller 

 star, although its presence is manifest from the peculiar jutting 

 of light on one side of the image of the primary. But in an 

 instant the disturbing undulations pass, the air steadies, the 

 image shrinks and sharpens, and two points of piercing bright- 

 ness, almost touching one another, dart into sight, the more bril- 

 liant one being surrounded by an evanescent circle, a tiny ripple 

 of light, which, as it runs round the star and then recedes, alter- 

 nately embraces and releases the smaller companion. The wash 



