132 



KNOWLEDGE 



[June 1, 1899. 



NEBULOUS REGION ROUND THE GLUSTER 

 N. G. C. NO. 2239 MONOCEROTIS. 



By Isaac Roberts, r.sc, f.e.s. 



THE region to which the annexed photograph refers 

 is comprised between E.A. Gh. 24m. IGs. and 

 E.A. 6h. 29m. 18s., and in declination between 

 4° 24-8' and 5° 5G-5' north. . Scale — one millimetre 

 to twenty-four seconds of arc. 

 Co-ordinates of the fiducial stars marked with dots for 

 the epoch 1900. 



star (.) D.JI. No. 1271 Zone +5° E.A. fill. 25m. 30-7s. Dec. N. 5° 517' Mag. 87 

 ■ „ (..) „ 1288 „ +4° ,, 6h. 25m. +47s. ,, 4^35-2' „ 8-S 



.„.(.,.). i, 130? „. +5" ,. 6h. 2Sm. 4«--ls. „ 5° 12-5' „ 8'3 ' 



Eeferences to parts of this region have been made by 

 Sir J. Herschel in the G. C. 1420, and by others in the 

 N. G. C. 2237-38-39; also in the Axt. Nach., No. 2918, 

 pp. 253-4, Astron. and Astro- Physics, Vol. XIII., p. 178. 



The photogi'aph was taken with the twenty-inch reflector, 

 and exposure of 2h. 45m., on 1899, March 5th, and 

 presents the object to us in complete form, and with much 

 detail, so that we rnay draw inferences, and also pass on 

 to future astronomers' records, of a reliable character, for 

 correlation with others that will be taken in future years, 

 when changes in the structure and positions relatively 

 with the stars can be detected. 



The photograph depicts the nebulosity as extending 

 about seventy-seven minutes of arc in south followimj to 

 north precedijui direction, and about sixty-seven minutes 

 from north to south, like a cloudy mass broken up into wisps, 

 streamers, and curdling masses — densely dotted with stars 

 all over its surface and over the regions surrounding — 

 many dark areas with and without either stars or nebulosity 

 in them. Other areas have both faint stars and faint 

 nebulosity in them, and they are shown to the faintness 

 of about eighteenth rpagnitude. Some remarkable black 

 tortuous rifts meander through the nebulosity on the north 

 precedinr/ half of the nebula; their margins are sharp 

 and well defined in the midst of dense nebulosity. They 

 are as cleanly cut as we see the caijons of great rivers, but 

 their width may in reality be millions of miles, for we have 

 no reason to assume that the nebula is nearer to the earth 

 than are the stars. It. is indeed possible that the stars 

 which dot the surface are nearer to us than the nebula. 



Speculations as to the further development of this nebula 

 (if it be one body and not several) cannot at present add 

 to our existing knowledge, nor can we picture by the 

 imagination what changes in its structure may be developed 

 in, say, a million years; but we have no basis for expecting 

 that more than microscopic changes can be detected in a 

 human lifetime. Let us take these hints for what they 

 are worth. Here is the record made available to all who 

 may desire to exercise their imagination concerning this 

 .very large subject. 



Urttet. 



LThe Bditore do not hold themselves respocsible for the opinioDs or 

 statementa of correspondents.] • 



■ — " ♦• — 



THE LEaEND. OF. LOUaH DEREVARAGU. 

 . ' ' To 'the Editors of Knowledge. 



SiKS. ^Perhaps some of the fishermen who frequent 

 Lough Derevaragh in West Meath, when the "green 

 drake" is in- season, may like to hear the strange old 

 legeiid attached to its waters, as worded by Sir Henry 

 Piers of Tristernaght, in 1682. "Lake Direvreagh, in 

 the Irish language soundeth ' the lake of a severe or hard 



judgment,' thus called, I suppose, from the sad exclama- 

 tion of a poor fellow, of whom the story goes that in a 

 frosty season he attempted to drive a cow he had stolen 

 across the lake, the ice being strong enough, and he in 

 haste, he drove somewhat hard, and the cow chancing to 

 stumble or slide, fell, and in the fall broke one of her 

 legs. Hereupon, not knowing better how to dispose of 

 her, he kills her in the place, and with the help of his 

 companions carries ofl" the hide and flesh. When safe and 

 at rest he found he had forgotten his knife, immediately 

 he returns to the place where the blood and entrails of the 

 cow lay, which by this time had so far thawed the ice, 

 that when he drew near the ice broke under his weight, 

 and falling in, the ice closed again about his neck and cut 

 off his head. The man falling made a hideous outcry — 

 which was heard at a great distance — to this purpose, 

 ' Oh ! oh ! I have received a sad or severe sentence or 

 judgment.' " Sir Henry Piers also mentions that about 

 Lough Iron and Lough Direvreagh may be found " a small 

 fish without spot, of the shape almost of a herring, a fish 

 very pleasant and delightful, but not taken in large quan- 

 tities." He tells us it is only found in the month of May, 

 and sparingly, and adds, that " the natives call it ' goaske.' 

 I do not know how to English it." 



How much of the "Legend of Derevaragh Lake" maybe 

 founded on fact is doubtful, but certainly the inhabitants 

 of West Meath possess fertile imaginations and belief in 

 old traditions, as the following " cures " for toothache, 

 which are commonly practised, will show: — "A sufli'erer 

 seeks for a human skull containing teeth, and pulls out 

 one of these teeth by catching hold of it with his own." 

 Should this operation be properly performed he will never 

 again have toothache ! Another superstition is that if a 

 tree has been struck by lightning a piece of the charred 

 wood carried about in the pocket will prevent toothache. 

 But I might multiply such "cures," and will only ask the 

 readers of Knowledge if the " delightful goaske " fish has 

 ever been discovered in this century, and what it may be ? 



Frances I. Batteksby. 



Sir Norman Lockyer has lately been experimenting with 

 flexible film, with the idea of adapting it to spectroscopic 

 photography. The large concave Rowland grating which 

 Sir Norman is now using has twenty thousand lines to the 

 inch ruled on its surface, and is of twenty-one and a half 

 feet radius, giving a spectrum thirty inches long. The 

 focal field of this grating is considerably curved, and it is 

 therefore impossible to get a sharp photograph of the 

 whole spectrum on a glass plate — a difficulty which Sir 

 Norman bridges by the use of a flexible film bent to the 

 curvature of the field. The Kodak Company have sent 

 us a magnificent print of one of the photographs thus 

 taken, and it is without doubt the longest solar spectrum 

 ever photographed at a single operation. It is thirty 

 inches long, and shows the arc spectrum of iron, with a 

 comparison spectrum of the sun from wave-length three 

 thousand six hundred to five thousand two hundred. It 

 is hoped by using these films instead of glass plates at the 

 next solar eclipse a larger number of photographs may 

 be taken than hitherto in any given period of time. 



Arrangements are in progress by the British Astronomical 

 Association for the organization of two expeditions to 

 observe the total solar eclipse of May 28th, 1900 — the one 

 to Portugal, Spain, and Algiers, the other to the United 

 States. Members and their friends who contemplate 



