IMPROVEMENTS IN LIGHTING, AND IN APPARATUS, FOR LIGHT- HOUSES, SIGNAL, FLOATING, AND HARBOUR LIGHTS
Year: 1850

page_text: TO ALL. TO WHOM THESE PRESENTS' SHALL COME, I, WILLIAM
CRANE WILKINS, of Long: Acre, in the: County of Middlesex, Engineer, send
greeting.
why
•
WHEREAS by Royal Letter's Patent under the Great Seal of Great Britain
and Ireland, bearing date at Westminster, the,Seventh day of November, in.
the fourteenth year of the reign of Her present most Excellent Majesty!
Queen Victoria, Her said Majesty did give and' grant unto me; the said.
William Crane Wilkins; my exors,iadors; and, assigns, Her especial licence,,
full power, sole privilege and authority; that I, the said William Crane,
Wilkins, my exors, adñññors, and assigns, and such other as I, the said-William,
Crane Wilkins, my exors, admors, and assigns, should at any time agree with,
and no others, should and lawfully might make, use, exercise, and vend, within
part of Her said Majesty's United Kingdom of Great Britain and Ireland
called England, Hér Dominion of Wales, and Town of Berwick-upon-Tweed,
and in the Islands of Jersey, Guernsey, i Alderney, Sark, and Man, and in all
Her Majesty's Colonies' and Plantations abroad; certain. Inventions, partly
communicated,' of "IMPROVEMENTS IN LIGHTING, AND IN APPARATUS, FOR LIGHT-
HOUSES, SIGNAL, FLOATING, AND HARBOUR LIGHTS;" in which said Letters. Patent
is contained a proviso obliging me, the said William Crane; Wilkins, to cause
a particular description of the nature of the said Inventions, and in what

page_text: manner the same are to be performed, under my hand and seal, to be enrolled
in Her said Majesty's High Court of Chancery within six calendar months
from the date of the said Letters Patent.
NOW KNOW YE, that in compliance with the said proviso, I, the said
William Crane Wilkins, do hereby declare the nature of the said Inventions
to be duly ascertained and described, and in what manner the same are to be
performed, in and by the following statement thereof, reference being had to
the six Sheets of Drawings hereunto annexed, and to the several letters and
figures marked thereon (that is to say) :-
-
My Invention of improvements in lighting, and in apparatus for light-
houses, floating and other lights, relates, first, to the peculiar arrangement of
the lenses and apparatus connected therewith by which to produce glares of
light and eclipses in alternate succession; secondly, to the application of
lenses to floating lights, whereby the rays of light are concentrated and
transmitted by refraction instead of reflection, as is ordinarily the case; and,
lastly, to the application of improved lenses to signal, harbour, and other
lights.
In reference to the first part of my improvements in the production of
lights and eclipses in succession, I have, in Sheet A of the Drawings
annexed, given illustrations of the arrangements hitherto adopted in the drums
of revolving lights, as also my improved arrangements by which means my
improvements will be more clearly elucidated.
Figure 1, Sheet A, represents a horizontal section of Figure 2 on the
line 1, 1, which is an elevation of the revolving and stationary drums adopted
hitherto. A, A, A, is the stationary drum wheel, consisting of eight or other
number of lenticular pannels D, D, which are formed so as to diffuse the light
uniformly throughout the horizon, but by their refractive powers to concentrate
the light vertically, and throw it off in parallel rays from the drum. Now in
order to produce glares of light and. eclipses in succession, a frame B, B, is
placed so as to encircle the drum A, which frame B, B, is fitted with four or
other number of panels C, C, C, C, and caused to rotate about its centre.
These panels C, C, are formed of a vertical lens, and prisms which collect
the whole of the rays emerging from the. arc of the fixed drum A A, covered
by the panels C, C. The light by this means is concentrated, and instead of
the rays emerging from the whole 45° of the horizon thus occupied, it will, be
confined to seven or other number of degrees, according to the lens, producing
a glare of light during the time occupied in the rotation of the drum through
the focal point, while the remaining number of degrees on either side will be
in obscurity. The glare of light thus transmitted is necessitated to pass

page_text: through two lenses, which more or less detract from the brilliancy of the light,
and moreover the apparatus is expensive in its construction.
According to my improved arrangement, which is exhibited at Figures 3
and 4, I dispense with the fixed drum hitherto employed. Figure 3 repre-
sents a horizontal section on the line 2, 2, of Figure 4, which is an elevation
of my improved rotating drum D, D; are four or other number of lenticular
pannels, such as described with reference to Figure 1, which transmit and diffuse
the light throughout their entire horizontal range, but refracting and conveying
the rays vertically. To the same frame E, E, are fitted annular lenses F, F,
which
оссиру the spaces on the periphery of the drum between the lenses D, D,
that is to say, each of the lenses alternately occupy 45° of the circle in case of four
being employed, as shewn. The annular lenses F, F, consist of a central lens,
having a spherical external surface, with a series of concentric rings so formed
as to converge and concentrate the rays of light in every direction. The rays
of light, by the refractive powers of the annular lenses F, F, will be trans-
mitted through the lens to an extent (by preference of 7). These alternate
lenses constitute the rotating drum, to which motion is communicated in the
ordinary manner, to produce glares of light and eclipses at the desired inter-
vals. This, as also other arrangements of the lenses to produce less or more
frequent eclipses, will be readily understood. By means of this rotating drum
the light will be transmitted through the lenses D, D, in a direct line to an
object, as in the fixed drum of the old light while within its horizontal range,
the continuous motion of the drum interposing one of the annular lenses F, F,
when the light will be obscured until the centre thereof has arrived, nearly
opposite the object, when a glare of light will be presented, succeeded by an
eclipse, until the annular lens passes from between the light and the object,
when the long interval of light will be transmitted by the next succeeding
lens D. From this it will be seen that the light does not suffer from the
intervention of two lenses in its transmission, and that the whole apparatus is
much less cumbrous and less expensive in its construction compared with the
method hitherto adopted.
Fig. 5, Sheet B, represents in elevation a lenticular apparatus of the first
order, which is furnished with what are called auxiliary lenses, which consist of
thirteen catadroptric rings G, G, surmounting the main drum of the light,
together with six similar rings H, H, immediately underneath. A less number
of these rings are employed for lights of an inferior order. The catadroptric
rings G, G, and H, H, form the only stationary medium for the refraction of
the light, and are so far similar to lights of a like character hitherto used.
These rings are sustained in their several supporting frames I, I,.I, erected

page_text: from the gallery K, K, and constituting the internal framework of the fixed
lenses. These catadroptric rings fulfil a like oflice with the rings D, D, of the
main druin before described, that is to say, they diffuse the light uniformly
throughout the horizon, but concentrate the rays of light in a vertical direction,
causing them to proceed in a direction more or less parallel to each other.
Sheet C represents several of the parts in detail; Fig. 6 being a vertical
section on a reduced scale, and Fig. 7 one wing or portion of the rotating
frame of this light. As before mentioned, the catadroptric rings G, G, and
H, H, constitute the only stationary part of the refracting elements placed
above and below the level of the light; the position between these rings
immediately surrounding the light is occupied by the drumi F, D, F. This
drum is the same in its construction as that represented at Figures 3 and 4,
and therefore does not require to be again described. The drum F, D, F,
is furnished with certain additions, whereby to collect and concentrate the rays
of light passing off from the catadroptric rings G, G, and H, H. The drum
F, D, F, is mounted on framework consisting of vertical stays L, L, and hoops
M, M, the whole surmounted and braced together by tension rods N, N, having
a centre common to all, fitted to a stud supported by the stationary framework.
The lower part of the rotating frame is carried by radial stays o, o, fixed to a
lower gallery P, P, sustained in a central position by the rollers a, a. The
lower gallery P is supported on conical rollers b, b, in contact with two inclined
surfaces c, c, which sustain the revolving drum. The rollers are fitted in their
bearings so as to approach nearer to or farther from the centre of motion, and
in order to adjust them set screws d, d, are fitted to the frame e, e. By
turning the screws d, d, in one direction, the rollers b, b, will be carried towards
the centre, thereby elevating or adjusting the plane of the motion of the drum,
while on the reverse motion being communicated to the screws d, d, the rollers,
by reason of the gravity of the drums, will recede from the centre of motion.
By this means also any wear may be compensated. The rays of light from
the catadroptric rings are concentrated by means of panels R, R, fitted to the
rotating drum immediately above and below the annular lenses F, F, of the
main drum. The position of the panels R, R, which are composed of lenses
and prisms, is such that the rays of light refracted by the catadroptric rings,
and impinging on these lenses, will be concentrated, and a similar effect pro-
duced thereon as the lenses C, C, produce in the old arrangements, represented
at Figs. 1 and 2, Sheet A. The lenses R, R, being in the same vertical line
as the annular lenses F, F, the glare of light and eclipses produced by the lenses
R, R, will be coincident with the glare of light and eclipses produced by the
annular lenses F, F; thus, therefore, the effect of the simultaneous interposition

page_text: of the lenses R, F, R, between the light and an observer will be to produce a
brilliant glare of light equal to the whole height of the lantern. By communi-
cating rotatory motion to the drum and framework in the ordinary manner, short
eclipses and glares of light produced by the lenses R, F, R, will be succeeded by
long intervals of light transmitted through the cylindrical lenses D, D, as well
understood. The duration of the lights and eclipses will of course depend on
'the rate of motion of the drum, together with the number of lenticular panels
composing the drum, as the arrangement herein shown of eight lenticular panels
in the circle may be varied according to circumstances. The lenses R, R, are
constructed in manner before described with reference to C, C, in Figures 1
and 2; they are also shewn separately in front elevation and section at Fig.
7, Sheet C.
Fig. 6, which represents a partial section of the improved apparatus
described at Figure 5, also with Fig. 8 a plan, and Fig. 9 a portion of
the detail, exhibits improvements in rotatory lights which are intended to
light only a portion of the horizon. As constructed hitherto, such lights
illuminated the entire, or nearly the entire, horizon; the effect of which was
that the light on the land side is useless, but which, according to my
improvements is caused to produce a greater useful effect within the arc in
which it is required, besides materially reducing the first cost of the lighthouse.
For this purpose I construct the catadroptric or auxiliary parts G; G, to
illuminate 180°, or other portion of the horizon, while the drum or rotating
part is constructed of five panels, four of which are equivalent to the semicircle
of the auxiliary rings G, G; the fifth representing the extent of motion
communicated to the drum. In this case the cylindrical lenses are omitted
altogether from the drum, which consists solely of annular lenses, as shewn in
the plan, Fig. 8, and as représented by the dotted lines, Fig. 7, with the upper
and lower lenses R, R, the whole of which results in a series of glares alternated
by eclipses. The motion in this instance is a reciprocating rotatory motion
communicated by a spur wheel S to a toothed quadrant T fixed to the druni
frame. The shaft of the wheel S is supported by the fixed frame of the
apparatus, and is in communication with gearing, which causes it to. turn one
revolution in each direction, as is well understood in producing reciprocating
motion in lights and for other purposes. The extent of motion communicated
to the drum is equal to the width of one of the lenticular pannels, so that by
its partial rotation it may produce alternately the glare and eclipse as described.
In order to produce the greatest useful effect on the desired are of radiation,
the entire opposite side of the lantern is occupied by a reflector or reflectors,
which reduce and concentrate the whole rays impinging thereon to the focal

page_text: point, thereby increasing the brilliancy of the light on the side desired. In
situations where the light desired should only be visible throughout 90° the
catadroptric parts will only be required of a corresponding range (making
sufficient allowance to obtain a perfect light at each extreme, and fitted with a
corresponding portion of a drum having the necessary extension to allow of
the required motion thereof. The economy of construction in this latter will
be more apparent when it is seen that the rotating drum need only consist of
three pannels, whereas by the old method the entire drum is required. The
framework bearing gear U and table V connected with rotation of the drum
will not require particular description, as being common to lighthouses generally.
The second part of my Invention has reference to the application of lenses
for the refraction and concentration of the rays of light in floating lights, in lieu
of the system of parabolic reflectors hitherto adopted, by which a floating light
is rendered visible with the effect of two and sometimes three of the lights so
refracted at any point in the horizon, whereas by the system of reflection
produced by parabolic reflectors the horizon is illuminated only within the
field of those reflectors, while the remainder is in darkness. Sheet D
exhibits my improvements in these lights, Fig. 10 being a vertical section of
the lantern, and Fig. 11 a horizontal section. Through the focus a is a
mast of the light ship on which the lantern is supported; within the lantern
are supported, on gimballs, 4 or other number of lenticular apparatus, each
capable of lighting a horizontal field of 236°. The optical part consists
in each of a drum or cylindrical lens A, A, which concentrates or con-
verges the rays of light in a vertical direction, together with catadroptric rings
B, B, placed above and below the drum A, which refract and concentrate the
rays as before described. The 124° of the circle unoccupied by the lens of each
apparatus is fitted with a spherical reflector C, which throws back the light on
that side to the focus. These reflectors are hinged and open, in order to
permit the introduction of the hand to the lamp when required. D, D, are
the reservoirs for oil, which maintain its uniform level, as well understood,
the tube E, conducting the oil from the reservoir to the wick, passing through
an opening in the reflector F. The result of the combination of these lenses
and reflectors C, C, of these lights is, that at whatever point in the horizon a
spectator may be placed, he will receive at least a triple light. Supposing, for
example, the point G be selected, he will receive the light from the optical
part of, and from the reflector of apparatus No. 1, together with that from
the apparatus No. 2, while, supposing the point G¹ be selected, he will receive
from the lens, and from the reflector of apparatus No. 2, as also the light
from the optical parts of Nos. 1 and 3. Although 4 lenticular apparata are

page_text: represented in the Drawings, such may either be reduced or increased, as two
systems of lenses would be available for the illumination of the entire horizon;
while, on the other hand, an increase of their number would be attended with
greater brilliancy of effect.
The third part of my Invention, which relates to improvements in lanterns
for steam and other vessels, & consists principally in. the application of a
lenticular cylindrical drum, whose horizontal rays of light varies from 112° 30'
to 225°, and also to an improved candle holder for such lantern.
Fig. 12, Sheet E, exhibits a vertical section, taken at the axis.of. the
lantern. The lens A is comprised of 5 parts, a, a, A, a, a, of a construction..
similar to the cylindrical lens, diverging the rays horizontally, as before
described, but converging in a vertical direction, its appearance, as seen from
any point within its range, being that of a vertical bar of light. B is the focal
point, in which a wax candle is constantly maintained by the: spring candle
holder, which consists of a double case, containing the spring for elevating the
candle. The case E. is composed of two cylinders, placed one within the
other, and allowing of the introduction of. the spiral spring in its collapsed
state. F is a receptacle in the lower part of the lantern, in which the candle
holder is placed, the candle being sustained in a cup C, which receives any
running of the candle. The cup C is maintained in its position, while in use,
bý three guide rods L, in lieu of the tube usually, adopted, which prevents the
adhesion of the candle thereto by any guttering thereof. D is the burner
ring, uniting the guide rods L and sustaining the candle in position. The
candle I prefer for the purpose consists of a combination of three candles, as
represented in plan at Fig. 17, the ring D being separately shewn at Fig. 16.
His a reflector for the purpose of throwing back the rays of light impinging -
thereon; and, opposite to that of the range, to increase as much as possible
the light at the focal point B. G is a button for the movement of the metallic
band encircling the air holes J, J, to regulate the admission of air. . K is a
screen for excluding the external air as much as possible at the escape holes h,
thereby preventing its affecting the combustion, and at the same time main;
taining free vent for the hot air..
Figs. 13 and 14 represent. the suspension of the ship's lantern, and indicate
the position proposed to place these lights in. The spectator is supposed to
be immediately in front of the vessel, the lanterns being on either paddle.
boxes, and at the mast head. These Figures also shew enlarged representations
of.the. lanterns, shewing the mode of securing the same to the mast head..
. Fig. 15 represents a plan of the arrangements of these improved lanterns,
shewing geometrically the outline of the range of light of the whole of, the
'

page_text: Janterns, which are represented. in different colors, as usually adopted in ships'
lights.
Sheet E represents my improvements in signal lights and ships' lanterns,
the object of which is to obtain a greater amount of. light than is obtained by
the lanterns at present in use, and also to prevent the extinction of those lights
by the force of the wind.
Fig. 18, Sheet F, is a vertical section through the axis of the lanterns, and
Fig. 19 is a horizontal section through the axis. A, A, is a lenticular
cylindrical muff, composed of a central lense a, and of four rings a¹, a', repre-
sented separately in plan at Fig. 20. This cylindrical lens is of the same
construction as hitherto spoken of, having for its object to diverge the rays of
light emanating from the focus horizontally, while at the same time converging
them in a vertical direction. B, B, B, B, is the cage of the lantern, composed
of two parts, which are united by means of the iron rods or uprights C, C,
fixed by means of nuts and screws, or by collar pins. The uprights C, C, are
placed on the exterior, in order to preserve the lenses from shocks. D, D, a
ball, placed on the upper part for the escape of the hot air passing through
the openings E. G is a screen for preserving the burner from the action of
the outward air, which would pass through the openings E. H, openings in
the lower part of the lantern, for the introduction of the air destined to supply
the burner; these openings are regulated according to the state of the
atmosphere, by the aid of moveable band, similar to that in the lanterns
shewn in Sheet E. F, burner composed of.a wax candle k, maintained at a
fixed height by the candle holder J. The candle holder is composed of
1st, a spring case L, attached by the two projecting parts 1, l, to the bottom
of the lantern. 2dly, of three conducting rods or uprights M, directing the
ascensional movement of the candle; these uprights are placed at a small
distance from the candle, to prevent the adherence of the parts of the candle
which may happen to run, and which would hinder its regular ascension.
3rdly, of a conical ring N, regulating the height of the flame. 4thly, of a
cup O, pressing the candle against the ring, and receiving the products of an
accidental running of the candle. 5thly, of a spring R, which keeps constantly
raising the cup O towards the ring N, arriving at which point the combustion
of the candle is complete. P is a screw ring, for suspending the lantern.
q is an iron wire handle, serving for a similar purpose as the upper screw
ring. Thus suspended, the lantern cannot be subjected to any oscillatory
motion, except that resulting from the want of sufficient tension in the cords
attaching it. The handle 7 turning on the pivots u, v, shuts down when the
lantern is placed on an even surface.

page_text: These lights may be white or colored. The colouring is obtained by
the aid of cylindrical glass muff's placed concentrically inside the lenticular
muff, such as the red light V, V.
Fig. 21, Sheet F, represents a vertical section, and Fig. 22 a horizontal
section of another signal lantern, the whole of whose parts are the same as
those just enumerated, with the exception of the lenses which constitute the
improvement in this lamp, and is merely the application of the annular
lens A, before mentioned, applied to the lantern, by which the brilliancy of
the light is increased much beyond the powers of the lenses usually adopted
in signal lanterns. This lens may be applied on one or more sides of the
lantern, to shew the various colors, with suitable shades for eclipsing and
rendering them visible, as may be required. In order to increase the light
as much as possible, I place the reflectors at the back or unoccupied parts of
the lantern, to reflect back the rays of light. impinging thereon to the focal
point, as before described.
Having described the nature of my Invention, and in what manner
the same is to be performed, I would have it understood that what I
claim is,―
First, the arrangement of cylindrical lenses. or panels, and annular lenses
or panels, in the rotating drum of lighthouses, as before described with
reference to Figs. 3 and 4, Sheet A.
Secondly, I. claim the application of the panels or lenses R, R, to the
rotating drum of revolving lights, whereby the rays of light from the cata-
dioptric parts are concentrated, so as to produce a flash or glare of light
coincident with the glare of the annular lens, as described with reference to
Figs. 5, 6, 7, and 8, Sheets B and C. I also claim the mode of supporting
the whole lenticular rotating drum on conical rollers b, b, & inclined surfaces
c, c, together with the adjusting screws d, d, all as described and shewn at
Fig. 5, Sheet B.
Thirdly, the arrangement of rotatory lens lights, having a reciprocating
motion, as described with reference Figs. 7, 8, and 9, Sheet C.
Fourthly, the application of lenses to floating lights, such as described and
represented in Figs. 10 and 11, Sheet D.
Fifthly, the application of the cylindrical lens to ship lanterns, shewn and
described with reference to Fig. 12, Sheet E.
Sixthly, the improvement described with reference to the candle and candle
holder, described and represented in Figs. 12, 16, and 17, Sheet E, and also
18 and 19, Sheet F, consisting of the trilateral candle and guide rods, by
which its perpendicular is maintained.

page_text: Enrolled the Seventh day of May, in the year of our Lord One thousand
eight hundred and fifty-one.