A summary on William Barnett's patent UK No. 7615 of 1838, is given in "Gas and Petroleum Engines" by Henry De Gaffigny, translated by A. G. Elliott, London, Whittaker and Co., published 1898. This book is available for free as an ebook in the Gutenberg project.

Paragraph 7 in Chapter 1 informs us:

In 1838 William Barnett took out a patent for an engine based on the same principle as that of Lebon. Two pumps compressed separately the combustible gas and the air and forced the mixture under pressure into the cylinder. The explosion was caused by a small gas-jet, communication between it and the cylinder being set up at the right moment by a revolving valve. The gas-jet was situated in the valve itself, and was so arranged that during half a revolution it was turned towards the outside, and was then lighted by a second jet, and during the remainder of the revolution it communicated with the interior of the cylinder and ignited the explosive mixture. This was the first gas motor in which the ignition was from the outside, and in which the explosive gases were at the same time under pressure.



UK Patent 7615 of A.D. 1838

In his patent specification William Barnett of Brighton describes as a first embodiment a single acting explosive engine, in a second embodiment a double-acting explosive engine, and in a third embodiment a self-igniting explosive engine with a platinum sponge. Unfortunately the reference signs used in the first, the second, and the third embodiment differ from each other.


Single acting explosive machine

Barentt engine Fig. 1 from UK Patent

Fig. 1 shows a single acting explosive machine comprising a cylinder a with an open top, a piston b, a double-acting pump, which serves both to supply atmospheric air (to form one portion of the explosive mixture), and to draw off from the cylinder, during the descent of the piston b, the products or any portion of the unconsumed gas which may remain after the explosion of the mixture has taken place. The air enters the lower part of the pump by the valve d during the ascent of the piston f; and upon the descent of the piston the air is forced through the valve g into the receiver A situated below the cylinder.

Figure 9, is s pump for supplying the hydrogen or other inflammable gas which forms the other portion of the explosive mixture. The gas enters the pump by the valve k, Figure 9, upon the ascent of the piston or plunger of the pump, and by the descent of the same is forced through a delivery valve (not seen in the Drawings) into the receiver h; l is the slide-valve case, communicating at the bottom with the receiver b, at the middle part, with the cylinder by the passage m, and at the top with the inlet valve n of the pump c, by means of the eduction pipe o; P is the delivery valve to the upper part of the pump opening into the waste pipe r; s is the slide valve, by the motion of which the internal portion of the cylinder, below the under side of the piston b, communicates alternately with the receiver it and the eduction pipe o; t is a gas burner, at which s small jet of gas is kept burning during the time the engine is in operation; c is the igniting cock for the purpose of igniting the explosive mixture, the mode of effecting which, and the construction of the cock, will be best understood by a description of Figures 8 and 4, which are drawn to an enlarged scale.

Double-acting explosive machine

The Drawings, Figures 5 and 6, in the Sheet marked B, represent a double acting explosive engine. Figure 5 is a longitudinal section of the engine, and Figure 6 is an end elevation of the frame and pumps. a is the cylinder; b, the slide-valve case connected with the two receiving chambers c, c, into which the air and gases are forced by the three pumps d, e, and f; d is a double acting pump, which draws in air at the valves g and h, and forces it into the receivers through the valves i and k; e, Figure 6, is a pump open at top which draws in hydrogen or carburetted hydrogen at the valve l, and delivers it by another valve (not seen in the Drawings) into the same box as the valve i, whence it passes into the lower receiver c; f, Figure 6, is a pump open at bottom, the piston rod of which works through a stuffing box in the top of the pump. This pump draws in hydrogen or carburetted hydrogen at the valve m, and delivers it into the upper receiver c by the pipe n, which is connected to a valve fixed at the aperture o. These pumps, by means of the spur wheels y and q (indicated by red circles in Figure 5), make their ascending and descending strokes simultaneously with the ascending and descending strokes of the piston r. s is a pipe proceeding from the slide case to convey the products of the explosion, or any unconsumed portions of the explosive mixture from the cylinder, and having at its extremity a light hanging valve opening outwards; t, t, are two igniting cocks, the construction of which has been already explained. These cocks are placed over the gas burners v, v, in the position shewn in the Drawing. The cocks being open to the atmosphere, the gas within them is ignited by the flame from the burners v, v, and by turning the cock the flame communicates with the interior of the cylinder. x is the pipe which supplies the hydrogen or carburetted hydrogen gas to the pumps c and f.

The operation of this engine is as follows:— Let it be supposed that the lower receiver is charged with the explosive mixture, and that the slide valve be then moved so as to open the communication between the lower receiver and the cylinder at the under side of the piston, whilst the cylinder on upon the upper side of the piston communicates with the exit pipe S, the mixture in the lower receiver will immediately flow into the cylinder, and upon turning the lower igniting cock the mixture will ignite, and, by exploding, will expand and impel the piston to the top of its stroke, any air which may be above it being expelled through the eduction pipe S. During the ascent of the piston the pumps s and d are drawing in air and gas respectively, and the latter pump and the pump f are forcing air and gas respectively into the upper receiver c. Upon the piston reaching the top. of its stroke the slide is reversed, the explosive mixture is admitted above the piston, and upon the explosion taking place, the piston is driven to the bottom of its stroke.  If preferred, the eduction pipe may be connected to a double acting air pump, so as to exhaust the products of the explosion, or any unconsumed portion of the explosive mixture, from the cylinder on the eduction side of the piston.

Third embodiment - double acting explosion machine with spongy platinium as an igniter

In his third embodiment Barnett disclosed a sponge of platinum to be used as an igniter.

Claims of the Barnett Patent

First, the employment of a mixture of atmospheric air or oxygen with hydrogen, or carburetted hydrogen, to give motion to machinery by their explosive force within a cylinder, or other dose vessel, and whether producing a rectilinear or rotatory motion.

Secondly, I claim the employment of pumps to supply the requisite quantities of air and inflammable gases, and to regulate their several proportions, whether such air and gas be delivered by the pumps directly into the cylinder, or into an intermediate vessel; but I do not claim nor limit myself to the particular construction of pumps shewn in the Drawings.

Thirdly, I claim the construction and application or employment of the igniting cock shewn in Figures 4 and 6, and already described, as having within it a jet of gas which communicates alternately with a flame placed beneath the cock, and with the interior of the cylinder.

And I claim such cock, whether it be applied to engines in which the explosive forces of the mixed air and gases constitutes the motive power, or whether it be applied to engines in which inflammable gas is employed to create a partial vacuum, and thereby render the pressure of the atmosphere available as a motive power. I also claim its application as a valve to regulate the passage of steam or fluids for any purpose to which it may easily be edited.

Lastly, I claim the application, to the purposes of my said Invention, of the old described of igniting, by platinum the explosive mixture of gases, and the general combination of the several parts, or any equivalent mechanical arrangement of the machinery, for carrying my said Invention into effect, or for the purpose of forming or constituting an engine to be operated upon by the explosive force of inflammable gases; but I do not claim any of the parts separately when applied to other purposes or the general purposes of motive power produced by different means, except the igniting cock above mentioned.

And I further declare that the mechanical arrangements, herein-before described, are illustrative and explanatory only, and that I do not intend in all cases to limit myself thereto.

Now, such my Invention being, to the best of my knowledge and belief entirely new and never before used in that part of Her Majesty's United Kingdom of Great Britain and Ireland called England, Her said Dominion of Valse, and Town of Berwick-upon-Tweed, I do hereby declare this to be my Specification of the same, and that I do verily believe this my said Specification do comply in nil respects, fully and without reserve or disguise, with the proviso in the said heroin-before in part recited Letters Patent contained, wherefore I do hereby claim. to maintain exclusive right and privilege to my said Invention.

And lastly, I declare that I do not claim originality in the use of any of the substances or fluids employed either for the ignition of gases or the construction of the apparatus, save and except anil so far as relates to my said Invention; and although I have described many parts of the said apparatus, and shown the means of connecting them, which are not new, I have done so solely for the purpose of rendering my Invention clearly understood and to show the different combination of in any of the parts, anil not as claiming them; anil I.

In witness whereof, I, the said William Barnett, have hereunto set my hand and seal, this Sixteenth day of October, One thousand eight hundred and thirty eight.



Signed, sealed, and delivered in the presence of


Clerk to Mr. Scadding,

4, Gordon Street,

Gordon Square.


AND BE IT REMEMBERED, that on the Seventeenth day of October,

in the year of our Lord 1888, the aforesaid William Burnett came before our said Lady the Queen in Her Chancery, and acknowledged the Specification aforesaid, and all and every thing therein contained and specified, in form above written. And also the Specification aforesaid was stamped according to the Statutes made for that purpose.

Enrolled the Eighteenth day of October, in the year of our Lord One thousand eight hundred and thirty-eight.

The Lenoir engine