482 The approaching Total Solar Eclipse. [Oct., 



duration of totality were given to a single negative — which would 

 be clearly unwise — no satisfactory picture of the corona could be 

 obtained. 



The chief promise of the expedition, in our opinion, lies in the 

 number of skilled observers who have joined the two parties which 

 are to devote their energies to general observation. The names of 

 Mr. Lassell, Lieut.-Colonel Strange, and others (it is almost in- 

 vidious to particularize), afford a sufficient guarantee not only of 

 skilful observation, but also of a thoughtful study beforehand of the 

 modes of observation likely to be most successful. We cannot sup- 

 pose for a moment that such observers will be content merely to 

 renew the observations which have been made so often and to such 

 little purpose, — to tell us merely the oft-told tale respecting the 

 beauty and splendour of the corona, its colour, extent, shape, and 

 so on. Something much more definite is required, and that some- 

 thing, if it can be obtained (of which we have no doubt whatever), 

 is surely to be expected from the skilful astronomers who have pro- 

 mised to take part in the general observations to be made on the 

 corona. 



Let us consider a few of those points on which it is most desir- 

 able that information should be obtained. 



It has been observed by some astronomers that the structure of 

 the corona seems in places to be marked by the presence of curves 

 and striations, and sometimes even of complex portions, which have 

 been compared to "hanks of thread in disorder." It is most im- 

 portant that adequate telescopic power should be applied to deter- 

 mine how far this appearance is real, and what peculiarities may be 

 recognized in the curves, hanks, and striations, under telescopic 

 scrutiny. For this purpose the disc of the moon ought not to 

 occupy (as has been usually the case) the centre of a large field ; 

 but the brighter part of the corona close by the moon's limb should 

 be kept altogether out of the field of view. Further, different 

 powers should be employed, and the focussing for each should be 

 very carefully noted. For even those who reject wholly (as we 

 confess that we do) the theory that the corona is merely a pheno- 

 menon of the earth's atmosphere, must recognize the fact that the 

 appearance of the corona may be, and probably is, very much 

 affected by our atmosphere, through which it is necessarily seen. 

 So that some of the peculiarities which apparently belong to the 

 corona may in reality appertain to our own atmosphere. In this 

 case the focussing suitable for clear recognition of the causes of such 

 peculiarities would correspond to the relatively small distance of the 

 upper parts of our atmosphere, and would thus differ appreciably 

 from the focussing for celestial objects. It has been suggested that 

 " the use of a telescope of low magnifying power but first-rate de- 

 finition, a comet eye-piece being employed, would be desirable in 



