the reader to comprehend them, the most simple and familiar illustrations have always been adduced; it is hoped, therefore, that this addition will prove both useful and interesting.

The notes will be found to contain a variety of facts relative to, or connected with, the progressive improvements of a comparatively new but important art, originating with Messrs. Murdoch, Creighton, Clegg, Dr. W. Henry, &c., as well as references to other respectable sources from which information has been derived. In short, the primary aim and endeavour of the author of the subsequent pages have been, to furnish a concise, clear and familiar Manual of Gas-lighting, adapted for general use; and although his purposes may be but imperfectly accomplished, he entertains the hope that what he has effected will be found not unworthy of attention.

The author has to apologize for the following errors in the first sheet, which was passing through the press while his mind was deeply affected by the death of his eldest son, who made the drawings for the engravings by Mr. Lowry: some others may have escaped his notice, and he will feel obliged by their being pointed out, as well as for any suggestions which will conduce to the improvement of another edition, if it should be called for.

ERRATA, &c.

Page 2, in the last line but one, after the word upper the refer

ence (12) should be inserted.

6, line 8, read or, instead of and.

9,

11,

14,

84,

5, in the note, for brass, read glass tube.

9, in the note, after the word heat, insert, IF BURNT

WITH OXYGEN.

9, from the bottom, read, retorts lined with fire-clay. 11, instead of paper and wall, read, paper or wall.

N. B. The wood-cut given below, is a more correct engraving of the GOVERNOR than the one in page 48, which is defective in one or two points.

B

In the note at p. 33 of the History of Gas-Lighting, the year 1733 is given, on the authority of Beckman, as the period when the streets of Birmingham were first lighted by lamps; but Hutton states 1773, which is probably the more correct.

CONTENTS.

Explanation of Plates I. and II.

Introduction

Of the Nature and Properties of Carburetted Hydrogen

Gas

Of the Decomposition of Coal for the Purpose of

making Gas -

Of the Use of the Hydraulic Main

Of the Condensing Apparatus

-

Of the Purification of Coal Gas, &c.

Of the Gasometer, &c.

Of the Tar Cistern

Of the Mode of decomposing Tar to convert it into

Page

1

5

8

12

19

21

24

31

34

335

Of the Apparatus and Process for making Oil Gas, &c. 37
Of the Portable Gas Vessels, &c.

-

The Construction and Use of the Gas-Meter

The large Gas-Meter and Tell-Tale

The Gas Governor, &c.

The Pressure Indicator

The Apparatus for registering the Impurities of Gas - 55

The Instrument for ascertaining the Specific Gravity

of Gas

Of the Mains, Syphons, Service-Pipes, Valves, &c.

Of the Explosive Properties of Coal Gas, and the

Means of preventing Accidents from Explosions

-

56

Page

Of the Construction of Burners, Length of Flame &c. 77 Of the Method of comparing the Illuminating Power of different Kinds of Light

Of the Comparative Advantages attending the Use of
Lamps, Candles, and Gas

Table of the Specific Gravity of Oil and Coal Gas

82

89

100

Of the Methods of ascertaining the Purity of Coal Gas 101 Of Ventilation, Escapes of the Gas, the Adaptation of

the Pipes to the Interior of Houses, &c.

The Varieties and constituent Parts of Pit Coal

- 103

- 106

An Attempt to explain the Scientific Terms, and to elucidate the Chemical Principles which are connected with the Operations of Gas-Lighting, intended for the Use of those who may not previously have any Knowledge of Chemistry

- 108

た