The Montgomery advertiser., 1905-08-13

Astronomers are at present busily engaged in making preparations for a great event on August 30 On that day there will be total eclipse Of the sun There have been. however. so many total eclipses within the recol- lection of most of us that the question
 may we'll be asked as to why we are
 to pay any particular attention to this
 eclipse among the number. The req
 sons are easily stated. In the first place. the duration of totality at the best stations is fairly long. The com plete obscuration of the sun will last for three minutes and fifty seconds' No doubt under a combination or fa- vorable circumstances eclipses can ana do sometimes happen In which the duration of totality, as 1t is called, IS considerably greater. In some eclipses it has been indeed nearly twice as great. On the other hand, In many total eclipses which have been deemed worthy the attention of the astrono-
 mer the precious seconds Of totality have been barely half as many as those which will be available this Au- gust.
 But a special reason why we hear so much about the eclipse of this autumn arises from the fact that 1t can be seen ''- localities easily reached by a few days journey. The middle of the eclipse, that is the occurrence of to- tality at noon, can be observed by those who travel no greater distance than to the north of Spain. There. either at Burgos. or at place one third of the way from Saragossa to Madrid, or at Morelia. there will be good prospect of clear weather. and af nf orhltUnaat of = tural phenomena under the best possi-
 ble conditions for observation.
 Novel Methods of Observation. Of course, without leaving our own homes the eclipse of August will be visible to some extent It will De visible over the North Atlantic. and over a great part of Canada, and doubt
 less will be noted by many hundreds of thousands of observers it may here be mentioned that an eclipse of this kind can be observed on a bright day when the sun is high. in a manner which. though 1t may not be actually instructive from a scientific point of view, Is certainly pleasing and pictu- resque. This observation Is made. strange to say, not by looking up to the sum- but by looking down upon the ground. When the sun throws a shadow of tree on the road. the
 
 stices between the leaves. from bright
 spots, which though we may not ordi-
 narily notice the fact, are really images
 of the sun. when a large part of the
 disc of the sun is eclipsed, then the
 bright part is reduced to a crescent.
 and consequently each of the myriad
 little solar images on the ground pre-
 sent to us beautiful crescents.
 A most satisfactory way of observing
 the phenomenon is to obtain the as- sistance of a telescope, and then to ar
 range that the image of the sun shall
 be thrown on q screen. By this device
 obtained and the excessive brilliancy is
 suitably reduced. ~-.ss
 But the characteristic phenomena
 which make eclipses so important are
 never exhibited when the phase of the
 eclipse is no more than a partial one
 Complete extinction of the sun is
 necessary, or. in other words, 1t Is nec-
 essary for the observer to take up
 such a position. that the shadow of the
 moon shall pass over him as that shadow sweeps over the earth. It is
 with the object of getting into the
 track of the shadow that astronomers
 are now preparing for a visit either to Canada, or to Spain, or to Tunis, or to
 Egypt, for the line passes through Spain. The width of the shadow track is approximately 100 miles. but toward each end of the track the dura- ton of the totality diminishes, so that to see the eclipse under the most fa- vorable conditions a position should be | taken as near as possible to the cen tral line. The Path of the Shadow.
 Just nineteen minutes before noon