A METHOD FOR COVERING ANY KIND OR FORM OF BUILD- INGS WITH SLATE, IN SUCH A MANNER & WITH SUCH MATERIALS AS WILL WANT LITTLE OR NO REPAIR WHILE THE TIMBERS REMAIN GOOD; THAT SUCH COVERING CANNOT BE RIPLED BY WIND, OR HURT BY FROST, HAIL, OR SNOW, OR ADMIT OF ANY WATER PENETRATING FROM THE STRONGEST DRIVING RAINS
Year: 1772

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
RAWLISON, of Lestwithiel, in the County of Cornwall, Architect, send
greeting.
WHEREAS I, the said Charles Rawlinson, did, by my Petition, humbly
represent unto His Majesty that I had, after long study, labour, and expence,
invented and found out "A METHOD FOR COVERING ANY KIND OR FORM OF BUILD-
INGS WITH SLATE, IN SUCH A MANNER & WITH SUCH MATERIALS AS WILL WANT
LITTLE OR NO REPAIR WHILE THE TIMBERS REMAIN GOOD; THAT SUCH COVERING
CANNOT BE RIPLED BY WIND, OR HURT BY FROST, HAIL, OR SNOW, OR ADMIT OF ANY
WATER PENETRATING FROM THE STRONGEST DRIVING RAINS; THAT IT WILL SAVE A
THIRD PART OF THE EXPENCES OF COVERING WITH RAGSTONES OR LARGE SLATES,
ACCORDING TO THE METHODS NOW PRACTICED, AND WILL LIKEWISE SAVE A THIRD
PART IN TIMBER; AND THAT THE COVERING UNDER THIS NEW-DISCOVERED DESIGN
WILL NOT EXCEED ONE HALF THE WEIGHT, AS IN THE COMMON MANNER OF SLATEING,
THE PITCH OR HEIGHT OF THE ROOF NOT RISING MORE THAN ONE QUARTER PART OF
THE SPAN OR BREADTH OF THE BUILDING, WHICH WILL REDUCE THE QUANTITY IN
MEASURE ONE NINTH PART OF THE GENERAL MANNER OF SLATEING, AND WILL BE FAR
SUPERIOR IN BEAUTY TO ANY METHOD EVER YET EXECUTED, AND THAT THE SAME HAS
NEVER BEEN INVENTED BY ANY OTHER PERSON;" I therefore most humbly prayed His
Majesty to grant to me, my executors, adiñors, and assigns, His Majesty's Royal
Letters Patent for the sole exercising of the said Invention within His said
Majesty's Kingdom of Great Britain, His Dominion of Wales, and Town of
Berwick-upon-Tweed, for the space of fourteen years, according to the form of
the Statute in that case made and provided: And whereas, by the said Letters
Patent, under the Great Seal of Great Britain, bearing date the Twenty second

page_text: day of May, in the twelfth year of His said Majesty's reign, after reciting
the said Petition, and also reciting, that His Majesty, being willing to give
encouragement to all arts and inventions which might be for the publick good,
was pleased to condescend to my request, His Majesty, of His special grace,
certain knowledge,. and meer motion, did, for Himself, His heirs and suc-
cessors, give and grant unto me, the said Charles Rawlison, my extors,
adñiors, and assigns, His special licence, full power, sole privilege
and authority, that I, the said Charles Rawlinson, my extors, adñiors,
and assigns, and every of them, by myself and themselves, or by my or
their deputy or deputys, servants or agents, or such others as I, the said
Charles Rawlinson, my extors, adiiors, or assigns, should at any time agree
with, and no others, from time to time and at all times thereafter, during the
term of years therein expressed, should and lawfully might make, use,
exercise, and vend my said Invention, within that part of His said
Majesty's Kingdom of Great Britain called England, His Dominion of
Wales, and Town of Berwick-upon-Tweed, in such'manner as to me, the said
Charles Rawlinson, my extors, admors, and assigns, or any of them, should in
my or their discretions seem meet, and that I the said Charles Rawlinson, my
executors, administrators, and assigns, should and 'lawfully might have and
enjoy the whole benefit, 'commodity, and advantage from time to time coming,
growing, accruing, and arising by reason of the said Invention, for and during
the term of years therein mentioned, to have, hold, and enjoy the said licence,
powers, privileges, and advantages therein-before granted or mentioned to be
granted unto me, the said Charles Rawlinson, my executors, administrators, and
assigns, for and during and unto the full end and term of fourteen years from
the date of the said Letters Patent next and iminediately ensuing, and fully
to be compleat and ended, according to the Statute in such case made and
provided; in which said Letters Patent is contained a proviso that if I, the
said Charles Rawlinson, should not particularly describe and ascertain the
nature of my said Invention, and in what manner the same is to be performed,
by an instrument in writing under my hand and seal, and cause the same to
be inrolled in His Majesty's High Court of Chancery within four calendar
months next and immediately after 'the' date of those His said Majesty's
Letters Patent, that then His said Majesty's Letters' Patent, and all liberties
and advantages whatsoever thereby granted; should utterly cease, determine,
and become void, anything therein-before contained to the contrary thereof in
anywise notwithstanding.
NOW KNOW YE, that I, the said Charles Rawlinson, in compliance witli
the said provisoe, do hereby describe and ascertain the nature of my said

page_text: Invention, which is to be prepared in the manner following (that is to
say) -
Each slate squared on the edge of a large knife, to prevent their breaking
on the under side (which will weaken the edges); the three sides of each slate
so squared to any certain dimentions, keeping that side of the slate upwards
you intend to have so when in work, and the lower edge squared reverse, that
the ragged part may lye upwards when on the roof; the rafters sawed to
one inch and seven eights wide, and each rafter rabbited deep enough to
receive two thicknesses of such sort of slates the roof is intended to be
covered with, and five eights of an inch wide, leaving a piece in the middle
of the rafter five eights of an inch to receive. the screws or nails that fasten
down the capping slates. The rabbit of the rafter may be pointed with one
coat of lead and oil, and dry before used. The slates may be painted with
one coat of lead and oil in all part the cement touches, which will make the
cement incorporate the stronger. The timbers and slates thus prepared, and
the slates sorted to the breadths and lengths, proceed in the following manner
to cover the roof: Middle the length of the building, setting off from the
middle one half of the length of your largest slate each way, fasten your
rafters to the wall plate and purlins, that the slate will fit between the middle
pieces left on the rafter and laying on the rabbits; proceed in like manner to
fix all the rafters, diminishing their distance from the middle row to the size of
the slates you have squared, if any difference in the lengths. Begin to lay the
middle row first, observing to have two thicknesses of slate at the eaves,
whether with or without a shutter, to prevent damage by ladders if no shutter,
or by treading upon. If a shutter, the under slate of the eaves must be let
down near its thickness into the rafter at the upper part, leaded in cement,
and screwed down to the gutter board and rafter; if no gutter, to the fillett of
the cornice wallplate and rafter. The slate ill do eight inches wide if a
gutter; if a dropping eave, it should not be less than one foot wide. Proceed
to lay upper and broadest slate of the eave first, filling the rabbits with
cement, and bedding the lower edge in like manner on the under slate,
rubbing it well down on the said slate and in the rabbets; screw this slate
down in the rabbet of the rafters (proceed to lay a row on each side the
middle row in like manner). Then take the next broadest slate of the middle
course, fit the rabbets with cement, and lay on cement on the upper edge of the
eave slate one inch down; rub down this slate well in the rabbets, and letting
it lap one inch over the upper edge of the eave slate, driving a small nail or
brad into the rafters under the lower edge to prevent it from slipping down by
the rubbing the next slate over it; proceed in like manner with every slate

page_text: (using the broadest first) till you reach the ridge, the ridge slates may be either
mitered together, or one lap over the other its own thickness; add on each side
over the last slates another slate about four inches wide on each side of the
ridge; these two finishing slates lapping each other at the center, the contrary
way to the lower ones, well bed them in cement, and screw or nail them to
the rafters. This method will not require any ridge rowl of lea, but such may be
added if better liked of. When two rows are part compleated, put on the capping
slate about one inch and an half wide, with holes pierced through it about three
inches from each end, and one foot apart, first laying on a sufficient quantity of
cement over the rafter and filling up the rabbets, then rub down the capping
slate in the cement as low as possible, screwing it down to the middle part of
the rafter with inch flat-head screws, either brass or iron, first filling the screw
holes with cement; this done, clear off the cement well, both inside and
outside carefully, filling all places that may be found deficient; then paint
over the cement only on the outside with any colour you prefer. Roofs may be
covered with great safety without rabbeting, the rafters sawed out only one
inch and seven eights board by any depth or thickness necessary to the length
of the rarings between the purlins; sink the upper ridge of the lower slate
to the cave (or shutter) levell with the back of the rafter, that the upper eave
slate may bed over it. Let the slates be bedded in cement on the back of the
rafter, each slate to meet the other on the back of the rafter, taking off the
top corner of the lower slate one quarter of an inch in the length, and one
inch and quarter in depth, to give room for a nail to hold up the last slate
laid, till the capping slates are bedded and screwed or nailed down; two places
must be cut out at the edges of the slates that join each other, to let the screws
or nails pass that fasten the capping slates, each slate being well bedded in
cement both on the rafter and where they lap over each other, each lap to be
one inch; proceed with three rows till a sufficient quantity be layed. To begin
laying the capping slates, the capping slates must be cut and bored as in the
other method, bedded in cement, well rubbed down, and screwed or nailed to
the center of the rafter in the vacancy cut out between the slates on the back
of the rafter. When this is done, clean off the cement both from the in and
outside, and paint the outside cement as before directed. This method will
require the screws to be near two inches long, either flat or round headed, to
fasten down the capping slates; if nails, great care must be taken when they
are nearly driven down, otherwise they will break the capping slates. Slates
may be laid on rafters not rabbeted, as before described, and the capping
slates to follow in courses, in manner of the common slates, the capping slate
to lap over each in manner of the common slates, bedding them in cement flat

page_text: down on the common slates and screwed through the vacancys as before
directed. This method I prefer, being effectual and taking less cement.
Different methods of making cement to lay the patent slating in, either of
which may be used with great safety (except near the sea coast where the
rain penetrates, and is driven with great violence, in such case the following
cement To make a hundredweight, take of best whiting, sixty-six
pounds; of sea coal or wood ashes sifted fine, twelve pounds; of hard brick or
tile dust sifted fine, ten pounds; of dry white lead, six pounds; of dry red
lead, six pounds one hundred pounds; mix it and put it in an iron pott, heat
it well over the fire till all the moisture is entirely evaporated, keep it stirring
all the time; when well dryed, put to it three quarts of boiled and six quarts of
raw linseed oil; oil weight, seventeen pounds-one hundred and seventeen
pounds; reduced in heating five pounds; remains nett, one hundred and twelve
pounds. Mix the above well with the hand in a tray or on a board, then well
beat it till it becomes tough and soft, mould it thoroughly with the hand, and
examine whether all the materials are well incorporated; if they are, it is fit
for use.
Cement made after the following manner will effectually answer for
town houses or inland countries:-Best whiting, eighty-two pounds; sea-coal
or wood ashes, sifted fine, twelve pounds; white lead, dry, six pounds; raw
linseed oil, nine quarts or seventeen pounds-one hundred and seventeen
pounds, reduces in drying the whiting, &c. five pounds; nett weight, one
hundred and twelve pounds. Or thus:-Best whiting, ninety pounds; dry white
lead, ten pounds; raw linseed oil, nine quarts or seventeen pounds-one hun-
dred and seventeen pounds; reduced in drying five pounds; remains nett, one
hundred and twelve pounds. In the two last cases also, let the materials
be well dryed in an iron pott before mixed with the oil, and made up in the
manner first directed.
In witness whercof, I have hereunto set my hand and seal, this
Fourteenth day of August, in the twelfth year of the reign of His
said Majesty King George the Third, of Great Britain, France, and
Ireland King, Defender of the Faith, and so forth, and in the year of
housand coven hundred and coventy-two

page_text: Robert Kaines, of Gray's Inn, in the County of Middlesex, Gentleman,
maketh oath and saith, that he did see Charles Rawlinson in the Deed Poll
annexed named, sign and seal, and, as his act and deed, deliver the said Deed
Poll in the presence of Thomas Lloyd, of Gray's Inn aforesaid, Gentleman, and
of this Deponent; and that the names Charles Rawlinson appearing to be set
and subscribed at the foot of the said Deed Poll as the party executing the
same, and Tho Lloyd and Rob Kaines indorsed on the back thereof as
witnesses attesting the due execution of the same, are of the respective proper
hands writing of the said Charles Rawlinson, Thomas Lloyd, and of this
Deponent, Rob Kaines. Sworn at the public office the 8th of Sep 1772,
hofone
AND BE IT REMEMBRED, that upon the oath of Robert Kaines, the Deed
Poll aforesaid was inrolled word for word, as it is before written. And also the
Deed Poll aforesaid was stampt according to the tenor of the Statute made in
the sixth year of the reign of the late King and Queen William and Mary of
England, and so forth.
Inrolled the Eighth day of September, in the year last above written.