A REVOLVING VENTILATOR
Year: 1854

page_text: LETTERS PATENT to Henry Adams, of No. 3, Leonidas Terrace, New
Cross, in the Hamlet of Hatcham, in the Parish of Deptford, in the
County of Surrey, for the Invention of "A REVOLVING VENTILATOR."
Sealed the 23rd January 1855, and dated the 31st July 1854.
PROVISIONAL SPECIFICATION left by the said Henry Adams at the Office
of the Commissioners of Patents, with his Petition, on the 31st July
1854.
I, HENRY ADAMS, of No. 3, Leonidas Terrace, New Cross, in the Hamlet
of Hatcham, in the Parish of Deptford, in the County of Surrey, do hereby
declare the nature of the said Invention for "A REVOLVING VENTILATOR " to be
as follows:-
Two thin circles of metal (herein-after called disks) have their circum-
ferences set out or divided into a number of parts: from the determined points
on the circumference lines are drawn to the centres of the disks; these lines
on the metal are in part cut through with a fine file or metal saw, com-
mencing at the circumference and terminating at points (on the lines), all
equidistant from the centres of the disks, leaving a circle of metal around
the centres of the disks not cut through. In this latter circle small holes are
drilled, into which screws or pins, having their heads flush or level with the
surface metal of the disks, are fitted. The holes at the centres of the disks are

page_text: enlarged, so as to admit part of the ends of the roller to occupy the space;
but for a small size ventilator this will be unnecessary (the two disks with
their openings as cut through are alike). From the pattern, as above, these
can be cast.
The roller (the least possible larger in diameter than the internal circle of
metal left surrounding the centres of the disks, around the circumference of
which the cuts or openings terminate) perfectly round or polygonal, mado of
wood, metal, glass, or other suitable substance; its length, as may be required,
has a disk (made as above described) fitted to each of its ends, and by means
of the screws or pins they are fastened to the roller. The cuts or open spaces
in the disks must be fixed or fastened at right lines with each other, exactly
corresponding, end for end. In the centre of each end of the roller, fine
steel pins or pivots are placed; they serve as the axis of revolution of the
roller and fans; the latter forming angles of the circle, with the axis of the
roller as a centre.
The fans can be sheets, square or oblong pieces of glass, metal, wood, or
other suitable substance, according with the number of cuts or spaces there
may be in the disk, all made or cut alike in length and breadth, and of equal
weight and thickness with each other; are placed in the cuts or open spaces in
the disks situate at the two ends of the roller; the lines of the fans and roller
are brought close together, and there securely fixed by means of a cement to
the metal disks. The glass or material used being in length the same dimen-
sions as the roller, and the thickness of the two disks causes the planes or fans
to form a line level with each other at the two ends of the roller, and flush
with the outer side of the disks. Thus fixed, the axis of the roller is the centre
of a circle on which the roller and fans revolve.
The case is quadrangular, made of metal or hard wood, with a level internal
surface; has two holes drilled, one at top, the other at the bottom, at points
equidistant from the sides. Into these holes, screws, having fine threads, and
pivot holes at their ends, are fitted; the axis at the ends of the roller revolv or
turn in these holes, and the screws serve to adjust the ventilator to the frame
or case.
The action of the ventilator is as follows:-The fans of glass are fitted to
the roller, as before described, and are placed within a frame or case, planned
to the aperture where the ventilator is required. The screws with the pivot
holes receive the axis of the roller vertically, or it can be placed horizontally
and adjusted to the frame. The diameter of the roller and two fans (one each
side of the roller) stretches across the breadth of the aperture of the frame
and the height of the fans, in dimensions agreeing with the length of the

page_text: roller and two disks. The superficial space of the aperture is taken up to
within a line of the sides of the case or frame; so likewise fans project
outwards and inwards (as they surround the roller, making angles with the
circle from the axis of the roller). The rarefied air of the room passing in-
ternally on the one side of the fans, and the cold atmosphere without on the
other, causes the ventilator to revolv on the axis of the roller, and thus
causes a current of air to flow into the room. No direct draft can enter, by
reason of the fans or planes making direct angles with the axis of the roller,
and, when desired, its action can be entirely stopped and all air excluded, by
means of a cap or slide fitted at one end of the case.
This ventilator can be made to take up the whole or part of a sash opening
or square of glass, and can be removed at pleasure and the sash frames
reinstated in the place; and in case of shop fronts or sashes having shutters
it can be used.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Adams in the Great Seal Patent Office on the
27th January 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
ADAMS, of No. 3, Leonidas Terrace, New Cross, in the Hamlet of Hatcham,
in the Parish of Deptford, in the County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, hearing date the Thirty-first day of July, in the year of our Lord One
thousand eight hundred and fifty-four, in the eighteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Henry Adams, Her special licence that I, the said Henry Adams, my execu-
tors, administrators, and assigns, or such others as I, the said Henry Adams,
my executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "A REVOLVING VENTILATOR," upon
the condition (amongst others) that I, the said Henry Adams, by an instru-
ment in writing under my hand and seal, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal Patent

page_text: Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said Henry Adams, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, that is to say :-
1st. Two circles of metal (hereafter called disks), of brass, bell-metal, Ger-
man silver, or other metal of compact texture, and of sufficient thickness to
keep the horizontal line of surface, and to be made similar and divided as
follows:-Drill a fine hole through the centre of the disk, determine how many
fans you intend the ventilator to have, which, for example, shall be eight, divide
the number of degrees in the circle, viz. 360°, by 8, will give 45° as the angles
to be set off from the centre of the disk; for the place or position of each fan,
draw a line from the circumference of the circle passing through the centre as
a diameter; from the centre set off the respective angles of 45°, draw lines
from the centre to the respective angular points on the circumference of the
circle, the disks are now divided each into eight equal parts. From the
centre of the circle describe a small circle that shall have its radius equal to
the radius of the circle end of the roller (which will fill up that space); with a
fine metal lathe saw or file, commencing at the circumference of the outer
circle, cut away on and through the several lines that are drawn from the
centre of the disks to the angular points on the circumference, until you reach
the inner circumference of the smaller circle that surrounds the centre, which
is left for the roller ends, and must remain solid for the smaller size venti-
lators; let the apertures be of such a width as you intend the fans shall be in
thickness. When making the disks for the larger ventilators it is requisite to
have the disks stouter and of greater diameter, bearing in mind that hammered
metal adds strength and tenacity, and therefore they must not be unnecessarily
increased in weight or thickness. The lines for the fans are drawn on the
disks in a similar manner as before described, varying the angle of the circle
from the centre, according to the number of fans determined to be used, and
the following deviation is requisite:-After drilling the fine holes through the
centres of the disks, determine the diameter or thickness you intend having
the roller; with the radius of the roller diameter describe a circle around the
centre, as it is advisable to let through each disk a part of the roller, com-
prising the centre at the ends and a portion of the surrounding wood; the same
having been determined, with that radius describe another smaller circle on
each disk, the latter will be the internal circles surrounding the centres of
cach disk; then proceed as with the smaller disks, cutting away the metal on

page_text: the lines marked out on the same, commencing at the circumference and ending
at the intermediate circle which is left for the external circumference of the
roller ends; lastly, with a drill from the centre of each disk cut away the
metal to within the circumference of the inner circle surrounding each centre,
which being removed the latter smaller circles serve for the centres and parts
of the ends of roller to enter through the disks: To secure the disks properly
to the roller, there must be fine pins or screw holes drilled through each ring
of metal surrounding the centres on which the ends of the roller fix; the holes
must be countersunk on their outer surface, so that the heads of the screws
or pins may be flush with the metal. The large disks having the centres of
the ends of the roller let through them, are to have fine screw holes drilled
within the circumference of the intermediate circle, countersunk, as before
described, and through these holes pins or screws enter the roller ends, thereby
securing the same firmly together. One disk properly divided and clean cut
through in the parts necessary for holding the fans, roller ends, &c. (as a
model), casts can be made therefrom at a very small cost and a great saving
of labour. In making the disks or preparing them from castings, do them in
pairs, being particular that they form circles of equal size, centres true, and
that the angles correctly divide the circle into the number of required parts;
also, that the lines that are cut through coencide exactly, disk to disk, as upon
this depends much the nicety of fixing the fans truly and securely, as hereafter
will be explained.
2. The rollers is made of wood or hollow metal, and in figure must be
truly circular from end to end, or a polygon; according to the number of fans
so the roller must have sides; but I have found it advisable to use a perfect
circle, as near as art has enabled the skilled artisan to make. With respect
to the roller, those for the smaller ventilators are best made of wood, well
seasoned and varnished, the centre points at the ends have driven in fine steel
points or pivots, and let these pass through the centres of the disks. The
rollers for the larger ventilators have their ends turned and circumference
reduced to the thickness of the disks, so that their ends present the outward or
general line of roller and the inner or less circle, which latter is turned and
made exactly to coencide with the inner circle of the disk; the metal of the
latter is drilled away, to admit the centres of the roller through the same. Find
the true centres of the roller at each end, and drive in there fine steel points
or pivots. In case of useing hollow metal for the roller, pieces of wood for the
top and bottom must be fitted to the aperture at each end, let in about an inch,
and turned the same as wood roller ends. The rollers must be made in
diameter in proportion to the apertures and disks used.

page_text: 3rd. The fans can be made of sheet or plate glass, horn, talk, sheet metal,
wood, or other suitable substance, the lighter the material the better; and are
cut and arranged rectangular, or in any suitable other geometrical figure,
admitting of similar shaped substances passing through or around the same
aperture. In making the fans, it is requisite to be particular, whatever material
the same are formed out of, to obtain severally the same thickness and weight
as near as possible as when they are fastened to the disks and roller. The
equilibrium of weight around the axis of the circle is an important feature to be
obtained towards facilitating the revolution of the fans and saving unnecessary
friction. With respect to the fans, the greater the number placed in the disks
the less the angle of opening left, and by reducing them in number, it causes a
greater angle, and consequently quantity of air to enter at the same time;
the revolution will, therefore, be best accomplished by having a sufficient
number.
4th. The case in which the before-described parts forming the ventilator is
placed is made as follows:-First determine the height and breadth of the aperture
into which the same is to be fitted, which, for example, let it be six inches wide
by nine inches high. Take two pieces of sheet copper, of sufficient thickness not
to bend or deviate from the horizontal line from exposure to the weather, and
let them exceed in width the aperture about one inch, as the width is six inches,
and allowing for two strips of copper (which take up a part of the length of
the front line), each about one-fourth of an inch in width, and are placed on
each side of the fans vertically in front of the case (as will be more particularly
hereafter described), will leave five and a half inches as the breadth, less a line
on each side, which will be taken up in front by the breadth of one fan on each
side, and the diameter of the roller; this width of five and a half inches divided
by two gives two and three quarter inches as a radius of a circle, and that
space will be taken up in depth, so as to admit of the revolution of the roller
and fans; add to this the width of the sash bar, or the substance to which it is
to be fixed; also an allowance of metal in front, for the purpose of holding the
adjustment screws to the roller, and these several dimensions will give the
required depth. Proceed to make the top and bottom plates similar to each
other as follows:-Cut away the two angles of copper at the back line at each
end half an inch at right angles, and of sufficient depth to let in the plates
securely, so as to fix horizontally to the aperture, and when these angular
pieces are cut out the plates fit exactly the plan of the horizontal line of
opening, and leave a projection of half an inch on each side of the width, from
the extreme points of the angular projections; draw a line at the sides of the
plates that shall be a skew line, and reduce the front line of plates to a six

page_text: inch opening; cut away the half inch of metal on each side of the front on
skew line; solder on to the edges (not the front or back lines) slips of copper,
and then in a line with them inside similar slips of zinc, leaving a space
sufficient between them to slide in sheet glass, so as to glaize the sides; drill
holes for screws through the copper on that part of the back line of the plates
which aro let in and rest on the horizontal supports, and countersink these
holes on the tray sides of the plates, that the screw heads may go in flush with
the plates and fit screws to the same; drill two holes near to the zinc slips,
one each side of plates, but so as to be clear of the space taken up by the
revolution of the fans and roller; let these holes be equidistant from the front
and back line of plates; tap them for fine screw ends to enter; make two
standards of brass, steel, or iron wire of sufficient thickness or substance, their
object being to stiffen and support the top and bottom of the case, and to keep
the same in a parallel line to each other; make screw ends to each standard
with webs, the same as the screw holes; make four nuts to each standard, two
for each end. Bisect the front line of plates, ascertain the middle, and correctly
mark the points on each plate; do the same with the back line, and draw
a line from front to back. As before stated, it was requisite to make an
allowance of metal on each plate over and above what would be requisite for
the revolution of the fans and roller, and the line of metal that covers the
horizontal bar of opening; this extra depth must be made sufficient, and on
the line marked from front to back. At a suitable distance from the front tap
screw holes, having fine webs, make two adjustment screws of brass to fit the
same, having circular heads, and at the centres of the web ends of these screws
drill in fine pivot holes, for the purpose of receiving the steel pivot ends of
roller, and place one screw in each plate. The top and bottom plates are now
similar, and the adjustment screws are in the middle, near to the front line of
plates and pivot holes, in a lino vertical with each other. Take the two strips
of copper, as before mentioned, of one quarter of an inch in width, make them
in length equal to the height of the case, including the thickness of the two
plates; they are to be soldered on the inside, top and bottom of the case; or
otherwise, by making these slips a little longer, the ends can be turned at
right angles, holes drilled, and screwed into the top and bottom plates on
the outside of the case. The several parts are then adjusted to each other as
follows:-
5th. As to putting the parts together:-Take the roller, which must be in
length, including the two disks, equal to the height of the aperture, less the
thickness of the top and bottom plates, and the space of a line top and bottom,
in order to allow the fans a free revolution; fasten on to the roller a disk top

page_text: and bottom, and secure them to the same by means of the pins or screws,
taking care that their heads do not project above the level of the outer side of
the disks; drive in at each end of the roller in the centre fine well-tempered
steel points, leaving a sufficient length only from the outer face of the disks to
fit into the depth of the pivot holes, made at the web ends of the two adjust-
ment screws. Cut out of glass, sheet metal, talk, horn, or other suitable
substance the number of fans you intend the ventilator to have, taking care
that they are similar, and as nearly as possible of equal weight and thickness
with each other, and that in their height and breadth, when placed on the
roller, they should fill up the superficial space to within a line of the sides of
that opening or case. The disks placed on the roller must have the openings
on the lines that are cut away in right lines with each other, top and bottom
of the roller; into these openings you place part of the top and bottom of
each fan, seeing that the lines of the respective fans exactly correspond with
the outer circumference of the roller surface, and come flush top and bottom
with the outer surfaces of the disks. In order to fix the glass into the openings
of the disks, an equal quantity of white and red lead is used, mixed up with
drying oil to the consistence of strong putty, or plaster of Paris and strong
gum arabac; but the latter must be varnished over after it is set, to prevent
the action of the atmosphere. As the circles of the disks require to be enlarged
or contracted, according to the size of the ventilator, a due allowance and
consideration must be made, so as to allow sufficient length of the apertures in
the disks to take hold of the fans, and prevent them falling out or being
damaged by wind. Tho fans being fixed to the roller, as previously described,
should be tested, to see that they revolve within the circumference of a circle
(the width they are made to fit will represent the diameter of that circle); if
they do so at both ends within a line of the circumference it will suffice, and any
irregularity must be corrected until perfected. It is most advisable to be over
careful, antecedently to fixing any of the fans, to test the lines of the glass or
metal used, to see that they form true right lines, or whatever other geometrical
shapes adapted. Having put together the disks, roller, and fans, proceed to
place the same in the case, by placing the steel pivots at the top and bottom
of the roller into the screw holes of the adjustment screws; at the same time
screw into their holes the two standards, having each two inside nuts, pre-
viously adjusted to the required height of the case, and soldered to the
standards; bring the top and bottom plates of the case in a parallel line with
each other, resting on the internal nuts fixed on the standards, leaving the line
of space as required for the revolution of the fans within the case; fit on the
nuts to the outside screw ends of the standards, and screw them close down to

page_text: the outer surface of the top and bottoni plates, which securely fixes them in a
parallel position; place the steel points of the roller top and bottom into the
pivot holes made in the web ends of the brass adjustment screws; fit these
screws into their holes, and adjust the fans and roller to a clear bearing, that
they may have clear play on the pivot ends; place appropriate pieces of
glass at each side of the case, by sliding them in from the projecting angles at
the back line of the case into the tray sides of plates, and as these metal
groves extend from back to front on both sides of the case, top and bottom,
and would allow a free passage for the air to pass in at the sides of the fans,
take two strips of copper of equal width with the opening, allowing for a line
of space only next to the fan sides, and in height equal to that of the case,
and solder them securely to the top and bottom plates in front, thus stopping
the aperture both sides. The atmosphere can now only enter by means of
action directly upon the fans; fit to the holes at the back of the plates fine
screws, and securely fix the plates to the horizontal line of opening, making
the heads of the screws flush with the plates. And, lastly, either a metal or
a wood framed door, glazed, is made to fit the internal aperture, with hinges
and fastenings, so as to open and shut out at pleasure the action of the
ventilator.
6th. The cases for the ventilator can be made of zinc or drawn metal, and
glazed top, bottom, and sides; and by means of having a projection of metal at
the back of the case, equal to that of the depth of the sash bar, can, with
screws, be fixed to the same, and a metal frame door, glazed, fitted to the inside
opening of the case. In fitting the roller and fans to a metal frame, it is
requisite to have the front aperture of the case of a sufficiently thick substance
to retain its form, the corners truly at right angles, and the lines surrounding
the fans proper planes; the width of the top and bottom sides, into which
the adjustment screws are fitted into, must have a sufficient breadth of metal
to admit of their being properly fitted to the same. It can also be used in
outer walls or apartments made in a building, by removing the bricks sufficient
to form a square or parallelogram; to this space a thin metal case is fitted; the
revolving fans and roller are placed in the case, and a door or slide to open
and shut inside the room.
7th. The disks, roller, and fans can be applied when placed horizontally to
throw down a current of air into buildings by the following arrangement:-Let
the opening on a piece of stout sheet zinc be a parallelogram, and at the
middle of the two longest sides, close to the edges of the opening, make and
fix brass plummer boxes, or pieces of brass with holes drilled through them, of
the size sufficient to receive the steel pivot ends that aro inserted in the roller,

page_text: and let these holes be as close as possible to the level of the surface of the zinc,
and the pivot holes exactly correspond with the points marks made (the
middle) on the two longest sides or lines. Let the fans surrounding the roller
be made of sheet zinc or tin, cut true to the opening within a line of the sides,
and solder them into the apertures of the brass disks; now fix the roller with
the fans, &c., as above directed, in a horizontal position, the roller crossing the
aperture from the middle points of the two longest sides, and the steel points
at the ends of the roller; place in the brass bearings or holes, and then fix, by
soldering perminantly the roller; solder on to each of the longest sides, close
to the line of opening, pieces of zinc, in a perpendicular position to the plane
of zinc on which the opening is made; let these pieces exceed a trifle in
height more than the fans are in projection standing out from the roller; bring
the two side pieces within a line of the outside edges of the fans, but so as to
allow sufficient space for them to revolv freely on the roller, and fix them in
that position by soldering on at their upper lines or edges a top piece, exceeding
in length and breadth by a line the opening or parallelogram; thus done, the
wheel or fans are covered in, top and two sides, leaving open the two less sides,
through which aperture the air has a free passage. On the top of the case
place a metal figure, so as to turn with the wind and keep the open sides with
the current of the wind. By fitting the above to a circular zinc pipe, so that
the top may freely revolv, the pipe can be carried down any length through the
roof or external part of a building into the rooms below.
8th. The action of the revolving ventilator is as follows:-Having been
made and put together as described, it can be fitted into a sash square or
aperture; and in this case its action is vertical on its axis (roller and fans),
and the pressure of the atmosphere in this position is very small, comparatively
speaking. The revolution of the circle taking place upon the pivot points and
holes of the adjustment screws, the difference of tempriture of the atmosphere
within and without a room naturally causes a pressure in excess either onc
side or the other of the fans. The latter crossing or filling up the aperture
would be effected so much thereby as to admit of the ingress of the air on
the one side, and the egress or escape of the heated air on the other; and in
case of a current of air passing either right or left, or directly opposite the
opening, causes a revolution of the fans and roller on the axis of the circle,
and a current of air to pass in on the one side, and the heated or impure air
is driven out on the other, without causing a draft direct, which is prevented
by the air first meeting the fans, and the revolution of the ventilator within
the case.
If shutters are made to fit the inside of a sash, the ventilator
projecting from the vertical line of the outside stands free and clear from

page_text: damage, and the top and bottom sashes can be moved up and down, as in
the ordinary way; and in case of large squares in sashes, not requireing
such space for ventilation, an internal wood frame is made, and divided by
small sash bars, glazed either with sheet or ornamental glass, leaving a
sufficient aperture in the middle, into which the ventilator is fitted, and can be
removed at pleasure.
In witness whereof, I, the said Henry Adams, have hereto set my
hand and seal, this Twenty-fifth day of January, in the year of our
Lord One thousand eight hundred and fifty-five.
HENRY ADAMS. (L.S.)