506 PROFESSOR PIAZZI SMYTH ON THE 
effects of a total eclipse ; and that only those few persons who have actually seen 
it, really know what it is like. The phenomenon therefore, when seen, has, by its 
unexpected novelty, such a power of enchantment, as to hold all observers spell- 
bound. j 
If astronomers, however, will only take the trouble, they may learn to give a 
good account of this most interesting subject. To no one who really tries to learn 
to draw, is the power wholly refused, and every one may by practice improve 
their memory, as applied to drawing, as well as to anything else. The test 
of the proper degree of skill having been arrived at, would be the taking of half- 
a-dozen views of the progress of a sunset, during a certain number of minutes; 
while to copy a picture after a one-minute view of it, would give the means of as- 
certaining afterwards what were the probable limits of that person’s errors in 
light, shade, and form, without some estimation of which no astronomical draw- 
ing should be considered presentable. No drawing can be made perfect, any 
more than a numerical observation can. The one cannot be depended on to the 
minutest feature inserted on the paper, nor the other to the smallest fraction of 
a division read off from the instrument. The question in either case must be, 
what is the extent to which dependence can be placed? By knowing that the 
ereatest probable error of Tycno Braue’s observations was 3’, Kepter proceeded 
safely to deduce the elliptic theory of the planets: and if theories are ever to be 
based on astronomical drawings, the possible limits of error in every way must be 
ascertained, and published as anecessary appendage to the pictorial representation. 
I will not presume to say that I have arrived at the mark which is here pro- 
posed ; but I have practised myself in drawing from memory, as well as in hasty 
sketches from nature. My part, however, at Bue Island, was with a telescope, 
and but for the unexpected clouding of the sky, I might have seen nothing of the 
general effects; the clouds, however, absolving me from my special duty, enabled 
me at least to look round, and I hastily made pencil sketches of what I saw. 
These were coloured as soon as possible afterwards, and form a series of views, 
shewing the varying effects, through the short period of the totality, and in 
various directions. One of these views has been engraved with the present paper 
(Plate XIV.), and as far as one only can serve, may perhaps tend to give some- 
thing more of a local name and habitation in person’s minds, to the verbal de- 
scriptions of which there have been many good ones from various of the observers 
of 1851. 
I will only therefore add, that to understand the scene more fully, the reader 
must fancy himself on a small rocky island, on a mountainous coast, the weather 
calm, and the sky, at the beginning of the eclipse, 4, covered with thin and bright 
cirro-strati clouds. As the eclipse approaches, the clouds gradually darken, the 
rays of the sun are no longer able to penetrate through and through, and drench 
them in living light as before; but, as with clouds on an evening sky, they become 

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