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CHAPTER IX.

The Greenwich Observations the Type of Excellence.—Light, a bright Effusion.

-Light, its marvellous Glory and Beauty.-Immense Utility of Light to Vegetation.-Light purifies the Atmosphere.- Organic Matter in the Atmosphere.— Black and Coloured Rain.-Atmospheric Electricity manifested as Light.-Captain Robert Fitzroy on St. Elmo's Fire-Corpus-sant, or Holy Light.– Dr. Franklin's Opinion of the Lights.--Points of Light on Persons, etc.-Lights on Horses' Manes and Ears.—Luminous Snow Storm.- Popular Opinion and Sciences accord. - Aphlogistic Lamp from Electric Light. - Magnetism imparted by Lightning. - Velocity of Electricity.Atmospheric Electricity, its conditions.—Remarkable order of the Needle.-Recurring Periods of the Magnetic Needle.—The Eastern Declination of the Magnet. — Atmospheric Action in the Eastern Area.—The Electric Lights affect the Magnetic Needle. Transfer of Electricity analogous to Heat.--Alternate Magnetic States at Hobarton and Toronto.- Equivalent Volumes of the Colours of the Bow.—Light, Heat, and Electricity allied spirits.-The Electro Polar Circle. -A system of Perpetual Transfer sustains the whole.

CHAPTER IX.

REGARDING the “Greenwich Observations as the type and standard of meteorological research, and as a general repository of the most valuable facts, I cannot conclude the investigation of the recurring monthly periods of the atmosphere, without endeavouring to follow in the path which the great masters have marked out, and themselves have trodden. For

“ The lives of these great men remind us

We can make our lives sublime ;
And departing leave behind us,

Footprints in the sands of time.

“Footprints that perhaps another

Sailing o'er life's solemn main,
A forlorn and shipwreck'd brother,

Seeing, shall take heart again.

“ Let us then be up and doing,

With a heart for any fate ;
Still achieving, still pursuing,

Learn to labour and to wait.”

LONGFELLOW.

232

LIGHT, A BRIGHT EFFUSION.

The atmosphere is a compound of many materials, and is a world within itself. Each department has special and peculiar laws. Not only are there different materials, but likewise three distinct governing, presiding, or resident agents, or acting powers, viz. : light, heat, and electricity. My attention has principally been given to heat, as the agent concerned in the examples which I have adduced of the recurring monthly periods. But light and electricity cannot be excluded, and they remain to be considered.

In respect to light, I cannot introduce it more becomingly than in the bright effusion of Milton :

"Hail, holy light ! offspring of heaven first-born,

Or of the Eternal co-eternal beam,
May I express thee unblam'd ? since God is light,
And never but in unapproached light
Dwelt from eternity, dwelt then in thee,
Bright effluence of bright essence increate.
Or hearest thou rather, pure ethereal stream
Whose fountain who shall tell ? Before the sun,
Before the heavens thou wert, and at the voice
Of God, as with a mantle didst invest
The rising world of waters dark and deep,
Won from the void and formless infinite."

THIRD BOOK OF “PARADISE LOST.”

In the “Greenwich Observations,” the action of light is scarcely adverted to, except we regard the actinometer as indicating some feeble and transient effect. But such a glorious subject as light, which illumines the atmosphere, and moreover has such immense chemical and other qualities, which place it in the first rank

LIGHT, ITS MARVELLOUS GLORY AND BEAUTY. 233

as an atmospheric agent, cannot be excluded from our consideration.

Photography has of late years produced such marvellous and miraculous impressions as to excite our attention, and will I hope accomplish some delicate and refined instrument or mode of ascertaining the varying qualities and conditions of light.

For even light, subtle as it is, has hourly, diurnal, and seasonal periods, and doubtless recurring monthly periods, but which I have not a sufficient mass of facts to establish.

But with this exemption from the general rule, it is the source of all the beautiful scenery of the sky, of all those lovely colours which adorn the clouds. It forms all the picturesque portion, is the most enchanting and delightful study to all admirers of nature. What can exceed or indeed compare with the beauty of the rainbow, the glory of the sunsets, and their exquisite tints, disposed in the most perfect order of regularity. The scenery of the sky presents some of the grandest pictures from the pencil of nature.

Nor are they without their useful applications in meteorology as signs and indications of the weather, but alas ! how seldom noticed. The too sedulous devotion to our instruments prevents our homage at the shrine of nature. I know not a finer field of study than the pictures of the sky.

We are so naturally disposed to consider the sole use of light to be that of bestowing the invaluable blessing and glorious gift of vision, that we rob it of half its

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