IMPROVEMENTS IN THE CONSTRUCTION OF THE ROOFS OF HORTICULTURAL AND STUND RHILDINGS AND STRUCTURES
Year: 1866

page_text: LETTERS PATENT to William Howitt, of Manchester Buildings, Silchester
Road, Notting Hill, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF THE ROOFS OF HORTICULTURAL AND
STUND RHILDINGS AND STRUCTURES."
Sealed the 3rd October 1866, and dated the 4th April 1866.
PROVISIONAL SPECIFICATION left by the said William Howitt at the
Office of the Commissioners of Patents, with his Petition, on the 4th
April 1866.
I, WILLIAM HOWITT, of Manchester Buildings, Silchester Road, Notting
Hill, in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF THE ROOFS OF HORTI-
CULTURAL AND OTHER BUILDINGS AND STRUCTURES," to be as follows:-
The mode at present generally practised of constructing the roofs of build-
ings, especially those of large span, in order to combine strength with lightness,
is to employ the tension principle, the tension rods being used to take the
thrusting strain of the roof; and in timber roofs king posts and struts in
combination with cross timbers, or what is termed a truss roof, has been the
principle of construction commonly adopted, and in which a crushing strain of
the supporting materials of the roof has been the principle of construction.
Now by this Invention I propose to dispense with these two general prin-
ciples of construction to make the roof self-supporting without the aid of
transverse tension rods or timbers, so that the inside of the roof shall be a

page_text: I
clear open space throughout the entire length and breadth of the roof.
propose to effect this by the following means, that is to say, I form the prin-
cipals of the roof of a semicircular shape placed across the width of the building
and resting upon suitable supports or walls; these principals I arrange at
equal distances asunder and connect them together by tubes of metal, the ends
whereof have screws or threads formed about them, one screw being right-
handed and the other left-handed. These screwed ends are intended to screw
into corresponding shaped screwed holes formed in the sides of the principals,
so that upon turning round the said tube the principals will be drawn towards
each other. These tubes extend lengthwise of the building and are placed
about three feet apart around and between the semicircular principals before
mentioned, and in this manner I proceed to connect all the principals of the
roof together, the said tubes serving the double purpose of tie rods and to
carry the sheets of glass or other covering of the roof. When glass is em-
ployed I connect the several panes together as follows:-Throughout the
length of each of the aforesaid hollow tubes I screw a piece of wood fitting
upon the said tubes and embracing the same. The surface of these pieces of
wood are formed with two obtuse faces somewhat resembling in cross section
the letter V inverted or reversed, and to the lowermost edge of each piece of
wood I fix a piece of sheet lead projecting beyond the wood, so that when a
pane of glass has been laid against one of the faces of two of such said pieces
of wood the projecting part of the lead is turned over the top edge and against
the outside of the pane of glass, which is thus kept water-tight. The next
and uppermost pane of glass projects beyond the edge of the former pane and
rests upon the other face of the before-mentioned piece of wood, the glass
being firmly held in contact with the obtuse shaped piece of wood by screws,
one at each corner of the pane; by these means I do not require to use putty,
as commonly practised; and suppose the distances between the several prin-
cipals to be four feet six inches, I place three panes of glass eighteen inches
wide side by side with their edges in contact with each other, and finally cover
the junction of the edges with a narrow strip of sheet lead; the roof thus.
presents the appearance of a series of curved strips of lead. By this improved
mode of constructing roofs, the weight being equally distributed over the
entire surface of the roof, and by reason of the principals being of a regular
semicircular shape or sweep, the pressure will be in a vertical direction
throughout the entire surface of the roof, thus dispensing with the necessity
for employing, either tension rods or strong king posts and horizontal cross
timbers, as heretofore practised, the entire strain of the roof by this Invention
being taken by the walls or other supports of the roof, and this being exerted

page_text: in a vertical direction, as above stated. By these improvements roofs may be
made more elegant, much lighter, stronger, and considerably cheaper, more
weatherproof and easily repaired than by adopting the means heretofore
commonly employed of constructing roofs.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said. William Howitt in the Great Seal Patent Office on the
4th October 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HowITT, of Manchester Buildings, Silchester Road, Notting Hill, in the
County of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of April, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said William Howitt, Her special licence that I, the said William
Howitt, my executors, administrators, and assigns, or such others as I, the
said William Howitt, 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 "IMPROVE.
MENTS IN THE CONSTRUCTION OF THE ROOFS OF HORTICULTURAL AND OTHER BUILDINGS.
AND STRUCTURES," upon the condition (amongst others) that I, the said William-
Howitt, my executors or administrators, by an instrument in writing under.
my, or their, or one of their hands and seals, 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,
Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said William Howitt, do hereby declare the:
nature of the said Invention, and in what manner the same is to be performed
to be particularly described and ascertained in and by the following statement,
that is to say :-
.
The mode at present generally practised of constructing the roofs of build-.
ings, especially those of large span, in order to combine strength with lightness,.
is to employ the tension principle, the tension rods being used to take the
i

page_text: thrusting strain of the roof; and in timber roofs king posts and struts in
combination with cross timbers, or what is termed a truss roof, has been the
principle of construction commonly adopted, and in which a crushing strain of
the supporting materials of the roof has been the principle of construction.
Now by this Invention I propose to dispense with these two general principles
of construction to make the roof self-supporting without the aid of transverse
tension rods or timbers, so that the inside of the so that the inside of the roof
shall be a clear open space throughout the entire length and breadth of the roof.
I propose to effect this by the following means, that is to say, I form the prin-
cipals of the roof of a semicircular shape placed across the width of the building
and resting upon suitable supports or walls; these principals I arrange at
equal distances asunder and conuect them together by tubes of metal, the
ends whereof have screws or threads formed about them, one screw being
right-handed and the other left-handed. These screwed ends are intended to
screw into corresponding shaped screwed holes formed in the sides of the prin-
cipals, so that upon turning round the said tube the principals will be drawn
towards each other. These tubes extend lengthwise of the roof and are placed
about three feet apart around and between the semicircular principals before-
mentioned, and in this manner I proceed to connect all the principals of the
roof together, the said tubes serving the double purpose of tie rods and to
carry the sheets of glass or other covering of the roof. When glass is em-
ployed I connect the several panes together as follows:-Throughout the
length of each of the aforesaid hollow tubes I screw a piece of wood fitting
upon the said tubes, embracing the same. The surface of these pieces of
wood are formed with two obtuse faces somewhat resembling in cross section
the letter V inverted or reversed, and to the lowermost edge of each piece of
wood I fix a piece of sheet lead projecting beyond the wood, so that when a
pane of glass has been laid against one of the faces of two of such said pieces
of wood the projecting part of the lead is turned over the top edge and against
the outside of the pane of glass, which is thus kept water-tight. The next
and uppermost pane of glass projects beyond the edge of the former pane and
rests upon the other face of the before-mentioned piece of wood, the glass
being firmly held in contact with the obtuse shaped piece of wood by screws,
one at each corner of the pane; by these means I do not require to use putty,
as commonly practised; and suppose the distance between the several prin-
cipals to be four feet six inches, I place three panes of glass eighteen inches
wide side by side with their edges in contact with each other, and finally cover
the junction of the edges with a narrow strip of sheet lead; the roof thus
presents the appearance of a series of curved strips of lead. By this improved

page_text: .
mode of constructing roofs, the weight being equally distributed over the
entire surface of the roof; and by reason of the principals being of a regular
semicircular shape or sweep, the pressure will be in a vertical direction
throughout the entire surface of the roof, thus dispensing with the necessity
for employing either tension rods or strong king posts and horizontal cross
timbers, as heretofore practised, the entire strain of the roof by this Invention
being taken by the walls or other supports of the roof, and this being exerted
in a vertical direction, as above stated. By these improvements roofs may be
made more elegant, much lighter, stronger, and considerably cheaper, more
weatherproof, and easily repaired than by adopting the means heretofore
commonly employed of constructing roofs.
And in order to explain my said Invention as completely as possible I now.
proceed to describe the best means I am acquainted with for carrying the
same into practical effect, reference being had to the illustrative Sheet of
Drawings accompanying these Presents, and to the numeral figures and letters
of reference marked thereon respectively, as follows:-
DESCRIPTION OF THE DRAWINGS.
Figure 1 represents a side elevation, partly in section, of one form of con-
struction of my improved roof; Figure 2, a transverse and vertical section
thereof through the line A, B, at Figure 1; Figure 3, a top plan view of my
improved roof represented partly covered with glass; Figures 4 and 5, modi-
At each
fications of parts herein-after particularly described and referred to.
of the foregoing Figures I employ similar letters of reference to denote corre-
sponding parts in so far as such parts appear or can be seen at each of such
said Figures respectively.
:
A, A, are semicircular principals, of wood or metal, placed about ten or
twelve feet asunder; these principals I connect together either by tubes, rods,
or bars of metal at B, screwed by their ends into the principals, as exhibited
at Figure 1, which shews the tubes B formed with a right-handed screw at
one end thereof, and a left-handed screw at the opposite end; I prefer, how-
ever, to connect the tubes B to the principals in the manner exhibited at
Figure 4, where A¹ shews the end principal with a solid nipple a cast thereon,
and with a screw cut about it. The intermediate principals I form each with
holes either cast or drilled through them for the tubes to pass through, and I
further connect the said tubes to the principals and to each other in the
manner represented at Figure 3, upon referring to which it will be seen that
one end of the tube B is crewed against and on to the solid nippple a, and
the other end of the tube B has a screw cut around it about three or four

page_text: inches long, and this screwed part passes through the hole in the principal A
and is securely connected thereto by back nuts at 6, b. I then proceed to join
another piece of tube to the tube B by means of the screw nozzle at c, and in
this manner I proceed to connect the principals of the roof together throughout
its entire length; and if desirable I connect the said tubes with a hot-water
apparatus for warming the interior of the building. The Drawing, at Figures
1, 2, 3, shews only three principals, but it will be obvious that in long roofs
there would be several of such principals; those at each extremity of the roof
are made broader than the intermediate principals for the purpose of con-
necting thereto pieces of wood C, as at Figure 2, the said pieces being employed
to hold the end sheets of glass by their edges in proper position upon the
pieces B; a¹ are pieces of wood screwed to B, as at 6', and to the pieces a¹ I
fix pieces of sheet lead at c¹; the panes of glass are then arranged, disposed,
and fixed as follows:-Beginning at the bottom of the principals I place pane
of glass No. 1, and turn the piece of lead c' over the top edge of the pane;
pane No. 2 I rest on the lead c' and proceed to turn the next piece of lead c¹
over the top edge of this second pane, and in this manner I proceed until I
have fixed all of one row of panes of glass, and by the side of this row of panes
I fix another row with their edges touching the other row, and finally I cover
the points of junction of the two rows of panes with a strip of lead, as at D;
to make a weather-tight joint, and in this manner I proceed to glaze the entire
roof. I would here remark that in some cases I fix pieces 8 of half-round iron
about twenty inches apart to the pieces of wood, as at Figure 5, for the edges
of two rows of panes of glass to rest on, and if necessary I cover the points of
junction of the two rows of panes with a narrow strip of sheet lead. Referring
to Figures 1, 2, 3, E, are hinged flaps for ventilation; G, wall plates, serving
also as gutters to carry off water from the roof; the plates G are intended to
rest on pillars or walls which may have glazed openings or windows and doors.
The ends of the roof may be glazed in the usual way. H is the ridge board
of the roof. The above Invention applies also to the construction of "lean-to"
roofs in which principals are formed of a portion of a circle.
Having now fully described and set forth the nature and object of my
said Invention for "Improvements in the Construction of the Roofs of
Horticultural and other Buildings & Structures," together with the best
means I am acquainted with for carrying the same into practical effect, I
would remark in conclusion that I am aware of partly circular "lean-to"
roofs having heretofore been constructed, I do not, therefore, claim as my
Invention this description of roof except when the principals thereof are con-
nected together in the manner above described.

page_text: And I further declare my Invention to consist in, and I claim the mode
above described, with reference to the accompanying Sheet of Drawings, of
constructing the roofs of horticultural and other buildings and structures by
forming the principals of a semicircular form and tieing them together by
tubes or rods, thereby rendering roofs self-supporting and dispensing with the
necessity for employing tension rods or transverse and vertical timbers for
supporting the roof, as heretofore generally practised.
I also claim the mode set forth and described of glazing roofs, as above
stated.
In witness whereof, I, the said William Howitt, have hereunto set my
hand and seal, this Third day of October, in the year of our Lord One
thousand eight hundred and sixty-six.
WILLIAM HOWITT. (L.S.)