Clxxiv PROCEEDINGS—PERTHSHIRE SOCIETY OF NATURAL SCIENCE. 
of the Nebular hypothesis. Following these came Sir John 
Herschel, whose career as an observer extended from twenty years 
before the Queen’s reign until the beginning of the seventies. 
During that time, amongst other achievements, he did for the 
southern hemisphere of the heavens what his father had done for 
the northern,—mapping and cataloguing more particularly the double 
and treble stars and the nebulae. In 1838, the year after the 
accession, he published his classical “Outlines of Astronomy.” From 
1838 to 1874 Leverrier, the great French astronomer, was engaged 
in one of the most stupendous pieces of scientific investigation ever 
undertaken, namely, the analysis of the orbits of the planets and the 
determination of their positions for the next two thousand years. 
In recent Astronomy we have another example of these wonder¬ 
ful “ Discoveries by Prediction ” to which I have already referred, 
namely, the finding by Adams of the planet Neptune in the position 
which Leverrier calculated it should occupy, from its influence on the 
orbit of Uranus. In the same way a new comet was discovered in 1866, 
whose presence had long previously been foretold by Adams. 
In 1862 Schiaparelli showed that the meteors which shoot across 
the sky, particularly in August and October, instead of being the 
erratic bodies of which they were supposed to be the type, have their 
paths prescribed for them just as definitely as the planets. 
The greatest triumphs of modern Astronomy, however, have 
undoubtedly been achieved by the aid, first of the spectroscope, and 
secondly of photography. In connection with the former, the chief 
honour is due to Dr. Huggins and his colleague, Dr. Miller, and, 
after them, to Norman Lockyer. As the result of these researches, 
we now know a great deal not only regarding the chemical com¬ 
position of the Sun, but also regarding its physical condition and its 
internal structure. Indeed, in one sense, it may be said that we 
know more about the interior of the Sun than w r e do about the 
interior of our ow r n globe. Not only the Sun, however, but many 
of the infinitely distant fixed stars have by this wonderful instrument 
been chemically analysed—an achievement which to our forefathers 
would have seemed almost impious to have thought of. Even more 
wonderful, if possible, is the fact that by the same means we can also 
tell the rate at which these so-called “ fixed stars ” are approaching 
towards or receding from us in infinite space. 
Marvellous as are these revelations of the spectroscope, to my 
mind the most momentous truth they teach is the uniformity of 
matter throughout all the universe, thus proving that all has had 
a common origin, and opening up a new vista of wonder and 
adoration in contemplating the wisdom and omnipotence of the 
Creator of all. The advance of recent science, if viewed aright, 
instead of undermining this feeling, immensely strengthens it. 
IV.—GEOLOGY AND GEOGRAPHY. 
Seven years before the Queen came to the throne, namely in 1830, 
Lyell’s “ Principles of Geology ” was published, which laid down the 
lines which all modern Geology has followed. Before that date, 
