CONTENTS.
| CHAPTER I. | |
| Page. | |
| Invention of Spectacles and Burning Glasses | [1] |
| Examination of Opticians—Artful Impositions | [2] |
| Duke of Wellington and the Bubble Schemes | [4] |
| Basis of Optical Knowledge—Physiology of the Eyes | [6] |
| CHAPTER II. | |
| Failure of Sight and the Application of Spectacles | [10] |
| Lenses—how to determine their Focal Lengths | [12] |
| Brazil Pebbles—Periscopic and Parallel Lenses—Process of | [13] |
| Working—Tests of Quality—and Experiment | [14] |
| Railroad Spectacles—Neutral Tint Shades | [16] |
| Country-made Spectacles—Trial Box of Sight | [18] |
| CHAPTER III. | |
| A Visit to the Optician—Rules for selecting Spectacles | [21] |
| Spectacle Frames—Russian Remedy for Short Sight | [24] |
| Solid Blue Steel Spectacles | [26] |
| Anti-pressure Spectacles—Single Eye Glasses injurious | [27] |
| Prices of Spectacles | [28] |
| CHAPTER IV. | |
| Specious Quackery—Testimonial Writers | [30] |
| Amber Spectacles analysed—Puffing Advertisement | [33] |
| Opinions of Dr. Neill Arnott, Dollond, Curtis, &c. | [34] |
| Absurdity and Ignorance of Puffing Advertisers, | [36] |
| CHAPTER V. | |
| Instances of Gross Imposition—Clarified Crystals and Coloured Pebbles! | [37] |
| Naval and Military Officers—Definition of Law | [39] |
| Ladies and Spectacles—Persevering Roguery | [41] |
| An Old Clothes Man Metamorphosed | [43] |
| CHAPTER VI. | |
| Specimens of Puffing Advertisements, | [44] |
| Royal Patronage—Cataract Alarmists | [45] |
| Abstract of Act of Parliament | [46] |
| Newspaper Paragraphs, | [50] |
| CHAPTER VII. | |
| Provincial and Metropolitan Scheming | [52] |
| Public Cautions—Tricks at Brighton | [56] |
| Liverpool Mercury—Parabolic Cheats | [60] |
| CHAPTER VIII. | |
| Correspondence with the Duke of Wellington | [61] |
| —— Frederick Tyrell, Esq. J. Hodson, Esq. | [62] |
| Signatures of J. Soden, Esq., J. F. Ledsam, Esq., —— Alexander, Esq. | [64] |
| Correspondence with Robert Keate, Esq. | [64] |
| Pretended Discoveries, Humorous Scraps, &c. | [66] |
SPECTACLE SECRETS.
CHAPTER I.
“Science should be stripped of every thing that tends to clothe it in a strange and repulsive garb, and especially every thing that, to keep up an appearance of superiority in its professors over the rest of mankind, assumes an unnecessary guise of profundity and obscurity, should be sacrificed without mercy.”—Sir I. F. W. Herschel.
Spectacles and side-saddles, we are quaintly informed, became common in England in the reign of Richard the Second. The ancients, however, knew the power of burning-glasses, and one cunning rogue, we are told, discovered a new way to pay old debts, by means of a round stone or glass used in lighting of fires, with which he melted the bond, written, as usual in those days, on wax. Their burning glasses were spheres, either solid or full of water, their foci were consequently very short and confused. A long interval occurred before spectacles were constructed, and three hundred years elapsed between the invention of spectacles and telescopes.
Our eyes should have our nicest and most tender care, since it is by them we are familiarized with objects of the most exquisite interest and beauty, abounding on the earth we inhabit, and in the starry firmament above us:—
“My soul, while Nature’s beauties feast mine eyes,