Part 13

One Volume, post 8vo., price 3s 6d,

A BIOGRAPHICAL MEMOIR OF SAMUEL HARTLIB, MILTON'S FAMILIAR FRIEND,

With Bibliographical Notices of Works published by him; and a reprint of his Pamphlet entitled

"AN INVENTION OF ENGINES OF MOTION."

"Mr. Dircks's is the first careful attempt to make posterity his (Hartlib's) friend."--The Examiner, 18th February, 1865.

"A scholar-like little monograph, giving all the information that can be given about a man whose name occurs in the correspondence of almost every eminent literary or scientific person of the time of the Commonwealth."--The Spectator, 20th May.

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One Volume, post 8vo., with engravings, price 2s,

THE GHOST!

AS PRODUCED IN THE SPECTRE DRAMA,

POPULARLY ILLUSTRATING THE MARVELLOUS OPTICAL ILLUSIONS OBTAINED BY THE APPARATUS CALLED THE DIRCKSIAN PHANTASMAGORIA.

"Mr. Dircks gives us the benefit of all his progressive discoveries in the matter, from the paper first read at the British Association Meeting at Leeds, in 1858, to the more recent improvements, with full explanations of the machinery, apparatus, and processes adopted in these ghost dramas, and further favours the public with a number of new adaptations. As a curious description of these spectral illustrations, the book is most interesting."--The Technologist, January, 1864.

"A volume explanatory of the uncommonly clever and scientific "spectral illusion" which has of late fairly turned the public head."

The Dublin Builder, January 1.

"A few months ago all London was rushing off to see Professor Pepper's Ghost, as it was called, but which it now appears was the property of Mr. Dircks, and from which his good name was filched in a very unhandsome manner. Here then he tells us all about it, how the spectre was raised, and how we may ourselves at pleasure call spirits from the vasty deep."--The Bookseller, February 29.

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Transcriber's Notes

Page 36: changed "Sorbiere" to "Sorbière" (15. Samuel Sorbière visited the works at Vauxhall)

Page 61: changed "Jupiper" to "Jupiter" (of cloves, &c. to Jupiter;)

Page 83: changed "BD^2" to "BG^2" ({AG^2 + CB^2 + 4(OF^2)} = {AC^2 + CG^2 + BG^2 + AB^2.})

Page 83: changed "sqrt(10^2 5^2)" to "sqrt(10^2) + 5^2" ( ... = {5^2 + sqrt(10^2) + sqrt(10^2) + 5^2,})

Page 84: changed closing parenthesis to closing braces ( ... 9} = {25 + 10 + 10 + 25} = 70)

Page 84: changed "tangental" to "tangential" (tangential to the circle X)

Page 84: changed "Q" to "2" (making G n equal to 2AG - GD)

Page 84: added missing opening parenthesis in "(I have indicated this square by dotted lines.)"

Page 84: changed "+ 1'25}" to "× 25" ({76'5625 + 1'5625} = {3'125 × 25})

Page 84: changed "hypothenuse" to "hypotenuse" (the area of a square on the hypotenuse)