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A CATALOGUE OF OBSERVATIONS OF LUMINOUS METEORS. 131 
surveys that we must in great measure depend for the materials on which 
correct delineations of the three magnetic elements on the surface of the 
earth can be satisfactorily based ; and it is to the repetition of such surveys, 
from time to time, that we must look for the data on which a true theory of 
the secular variation of terrestrial magnetism may be founded. ‘Twenty 
years having elapsed since the execution of the former Magnetic Survey 
of the British Islands, the General Committee had deemed that the proper 
time had arrived for its repetition, and named a Committee for the purpose, 
consisting of the same five members of their body by whom the former survey 
was made, with the addition of Mr. Welsh, the Director of their Establishment 
at Kew. The present Report stated the progress which the Committee had 
already made, chiefly in England and in Scotland, and their expectation that 
at the next meeting of the Association they should be able to report that the 
work was drawing neur to its completion. 
Report on Observations of Luminous Meteors, 1856-57. By the Rev. 
Bapven Powe tt, M.A., F.R.S., F.R.A.S., F.G.S., Savilian Pro- 
fessor of Geometry in the University of Oxford. 
In submitting to the British Association my ¢enth Report of Observations 
on Luminous Meteors, I could have hoped that it might have contained 
some attempt at least towards the classification and generalization of the 
vast mass of results which have now been communicated, But while the 
actual contribution of fresh observations for the year which has elapsed since 
my last communication is not very extensive, I am also constrained to admit 
that I have as yet attempted very little towards the greater object in view. 
' In the present communication, nevertheless, besides the mere detail of 
observations, I am able to include notices of one or two important specula- 
tions on the subject which have been pursued by some eminent men who 
have turned their attention to this inguiry, and have followed out some 
generalizations on certain points connected with it, which seem eminently 
valuable towards the gradual establishment of a solid theory of meteoric 
phzenomena. 
I. Some generalizations respecting the causes of meteor-phznomena, espe- 
cially the averages of their horary variation in numbers through the night, 
have been advanced by Mr. G. C. Bompas, founded on the observations of 
MM. Coulvier-Gravier and Boguslawski. 
- The general result of those observations is, that the number of meteors 
varies through the successive hours from 6 P.M. to 6 A.M., by a regular 
increase up to the last-named hour. 
The number which appear in the East is more than double the number 
originating in the West; those from North and South nearly equal. In 
other words, nearly two-thirds of the whole number originate in the Eastern 
hemisphere of the sky. 
_ From the observations of Boguslawski and others, it appears that the ave- 
rage velocity of meteors is about double that of the earth in its orbit. 
Mr. Bompas, combining these facts, deduces the following theory, derived 
solely from the conditions of the earth’s motion. The greatest number of 
‘meteors is encountered when the observer's meridian is in the direction of the 
earth's motion, which is at 6 a.m.; and then decreases to 6 P.M., when he 
_ looks the opposite way. If the earth were at rest, meteors (supposed equally 
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