Regular dimensions and flat parallel faces except one, a header. Used
for decorative purposes in header-bond work. So not
malformed/kiln-rejects , perhaps single-part moulding rather than 2-part
moulding, relying on shrinkage for mould release, prior to firing. As
that face , only, is slightly convex , like part of the surface of a
sphere about the size of a space-hopper perhaps. Not bullnose header or
radial header, convex header googles nothing sensible.

"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size of a
space-hopper perhaps. Not bullnose header or radial header, convex header
googles nothing sensible.

This shows different types of radial headers

http://www.bovingdonbricks.co.uk/spe.../radial-bricks

as you can see, some of them take 72 bricks to form a quadrant but others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across

On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size of a
space-hopper perhaps. Not bullnose header or radial header, convex header
googles nothing sensible.

This shows different types of radial headers

http://www.bovingdonbricks.co.uk/spe.../radial-bricks

as you can see, some of them take 72 bricks to form a quadrant but others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat

"N_Cook" wrote in message
...
On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size of
a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

This shows different types of radial headers

http://www.bovingdonbricks.co.uk/spe.../radial-bricks

as you can see, some of them take 72 bricks to form a quadrant but
others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat

So it bulges out both side to side and top to bottom on that one end only? -
rounded like a balloon?

On 17/01/2015 19:41, Phil L wrote:
"N_Cook" wrote in message
...
On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size of
a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

This shows different types of radial headers

http://www.bovingdonbricks.co.uk/spe.../radial-bricks

as you can see, some of them take 72 bricks to form a quadrant but
others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat

So it bulges out both side to side and top to bottom on that one end only? -
rounded like a balloon?



yes, but less curvature than a party balloon , perhaps more like the
flatter curvature of a space-hopper

"N_Cook" wrote in message
...
On 17/01/2015 19:41, Phil L wrote:
"N_Cook" wrote in message
...
On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects
,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size
of
a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

This shows different types of radial headers

http://www.bovingdonbricks.co.uk/spe.../radial-bricks

as you can see, some of them take 72 bricks to form a quadrant but
others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat

So it bulges out both side to side and top to bottom on that one end
only? -
rounded like a balloon?



yes, but less curvature than a party balloon , perhaps more like the
flatter curvature of a space-hopper


Are you sure they actually exist because I've never seen one.
If it's an existing wall, the only thing I can think happened was that the
builders did actually use seconds / rejects that were all malformed on one
edge only

On 17/01/2015 19:49, Phil L wrote:
"N_Cook" wrote in message
...
On 17/01/2015 19:41, Phil L wrote:
"N_Cook" wrote in message
...
On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects
,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size
of
a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

This shows different types of radial headers

http://www.bovingdonbricks.co.uk/spe.../radial-bricks

as you can see, some of them take 72 bricks to form a quadrant but
others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat

So it bulges out both side to side and top to bottom on that one end
only? -
rounded like a balloon?



yes, but less curvature than a party balloon , perhaps more like the
flatter curvature of a space-hopper


Are you sure they actually exist because I've never seen one.
If it's an existing wall, the only thing I can think happened was that the
builders did actually use seconds / rejects that were all malformed on one
edge only



I'm aware of 2 walls both header bond , in different towns, with this
brick type. I would guess the the curvature is too consistent to be
seconds or rejects, thousands of them , all this same profile, by sight
that is.

"N_Cook" wrote in message
...
I'm aware of 2 walls both header bond , in different towns, with this
brick type. I would guess the the curvature is too consistent to be
seconds or rejects, thousands of them , all this same profile, by sight
that is.


I've never seen one but I know that things like this are regional.

Is it possible that the bricks have worn down at the edges? - have you been
close up to the walls in question?

There aren't many buildings around these parts built in headers.
When i was 18 I worked in a street in Manchester and the bakery on the
corner was built entirely of headers, pale yellow ones IIRC.
I bought a chicken and mushroom pie from there one day and there was a fly
embeded in the pastry

On 17/01/2015 19:49, Phil L wrote:
"N_Cook" wrote in message
...
On 17/01/2015 19:41, Phil L wrote:
"N_Cook" wrote in message
...
On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects
,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size
of
a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

This shows different types of radial headers

http://www.bovingdonbricks.co.uk/spe.../radial-bricks

as you can see, some of them take 72 bricks to form a quadrant but
others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat

So it bulges out both side to side and top to bottom on that one end
only? -
rounded like a balloon?



yes, but less curvature than a party balloon , perhaps more like the
flatter curvature of a space-hopper


Are you sure they actually exist because I've never seen one.
If it's an existing wall, the only thing I can think happened was that the
builders did actually use seconds / rejects that were all malformed on one
edge only



This pic is very much false colour, very exagerated contrast
http://diverse.4mg.com/cobble-bricks.jpg
The sun is from the left at a shallow angle to the plane of the whole
wall, to cast what should have been obvious shadows, but even so in the
original pic its not so obvious as it is by sight. The curvature is not
really strong enough to make obvious shadowing.
So shadowing is to the right of each brick, about 4 o'clock posistion of
each brick

In message , N_Cook
writes
On 17/01/2015 19:49, Phil L wrote:
"N_Cook" wrote in message
...
On 17/01/2015 19:41, Phil L wrote:
"N_Cook" wrote in message
...
On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects
,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size
of
a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

This shows different types of radial headers


http://www.bovingdonbricks.co.uk/spe...special-shaped
-bricks/category/radial-bricks

as you can see, some of them take 72 bricks to form a quadrant but
others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat

So it bulges out both side to side and top to bottom on that one end
only? -
rounded like a balloon?



yes, but less curvature than a party balloon , perhaps more like the
flatter curvature of a space-hopper


Are you sure they actually exist because I've never seen one.
If it's an existing wall, the only thing I can think happened was that the
builders did actually use seconds / rejects that were all malformed on one
edge only



I'm aware of 2 walls both header bond , in different towns, with this
brick type. I would guess the the curvature is too consistent to be
seconds or rejects, thousands of them , all this same profile, by sight
that is.

I've never come across them either. Maybe a local thing? from the time
when bricks were made fairly locally?

What sot of age buildings are we talking about?
--
Chris French

On Saturday, 17 January 2015 19:17:39 UTC, N_Cook wrote:
On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size of a
space-hopper perhaps. Not bullnose header or radial header, convex header
googles nothing sensible.

This shows different types of radial headers

http://www.bovingdonbricks.co.uk/spe.../radial-bricks

as you can see, some of them take 72 bricks to form a quadrant but others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat

Quoins?
Corner stones.

On Saturday, 17 January 2015 20:14:52 UTC, N_Cook wrote:


This pic is very much false colour, very exagerated contrast
http://diverse.4mg.com/cobble-bricks.jpg

Idiot. Get a decent ISP.

"Weatherlawyer" wrote in message
news:83708c3c-586f-4143-bb82-
Quoins?
Corner stones.


An entire building built of corner stones?

Did you even bother to read any posts in the thread?

In message ,
Weatherlawyer writes
On Saturday, 17 January 2015 20:14:52 UTC, N_Cook wrote:


This pic is very much false colour, very exagerated contrast
http://diverse.4mg.com/cobble-bricks.jpg

Idiot.

You might want to reconsider who is being the idiot here?

Get a decent ISP.

That image isn't hosted by an an isp.
--
Chris French

On 17/01/15 19:17, N_Cook wrote:
On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size
of a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

This shows different types of radial headers

http://www.bovingdonbricks.co.uk/spe.../radial-bricks


as you can see, some of them take 72 bricks to form a quadrant but
others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat
bullnose brick


--
Everything you read in newspapers is absolutely true, except for the
rare story of which you happen to have first-hand knowledge. €“ Erwin Knoll

In message , The Natural Philosopher
writes
On 17/01/15 19:17, N_Cook wrote:
On 17/01/2015 18:40, Phil L wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size
of a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

This shows different types of radial headers


http://www.bovingdonbricks.co.uk/spe...cial-shaped-br
icks/category/radial-bricks


as you can see, some of them take 72 bricks to form a quadrant but
others
only take 6.

The largest circle would be 5.4m across and the smallest 450mm across



That is for radial bricks. The ones I'm trying to name are for regular
plane flat walls , but header-bond. The curving is just on the external
exposed headerof each brick (not the usual flat), so the overall surface
looks traditional cobble surface, rather than flat
bullnose brick


The OP specifically says it isn't bullnosed, which is a different shpae
than he descibes
--
Chris French

On Saturday, 17 January 2015 20:45:53 UTC, Phil L wrote:
"Weatherlawyer" wrote in message
news:83708c3c-586f-4143-bb82-
Quoins?
Corner stones.


An entire building built of corner stones?

Did you even bother to read any posts in the thread?

There was nothing in the the OP to say that the whole building was made of quoins although judging from the mettle of your post ...

(There aren't many buildings around these parts built in headers.
When i was 18 I worked in a street in Manchester and the bakery on the
corner was built entirely of headers, pale yellow ones IIRC.
I bought a chicken and mushroom pie from there one day and there was a fly
embeded in the pastry)

....even you might have noticed that such a thing was not impossible if somewhat unusual. However given their calibre (see example above) one would be a fool to force one's self to read the gamut of fly ridden stories such as your.

"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size of a
space-hopper perhaps. Not bullnose header or radial header, convex header
googles nothing sensible.

ISTR I saw bricks like that years ago.
No apparent reason for them, I assumed they were just cheap bricks and they
were that shape due to the (dodgy) manufacturing process/clay they were made
from.

On 18/01/2015 08:18, harryagain wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size of a
space-hopper perhaps. Not bullnose header or radial header, convex header
googles nothing sensible.

ISTR I saw bricks like that years ago.
No apparent reason for them, I assumed they were just cheap bricks and they
were that shape due to the (dodgy) manufacturing process/clay they were made
from.



I think I'm coming round to that opinion. Why make a profile that is so
subtle that you can only see the effect with a glancing sun angle and
even then not that pronounced
http://diverse.4mg.com/cobble-bricks2.jpg
natuaral colour pic, the lower left corner is in shade from a tree, so
dead flat looking. On reveiwing the pics I don't think the cobbling is
that consistent to be deliberate, some seem more "radial" shape of
curvature, on one axis only, and not "sperical"
The other wall is only obvious likewise in angled sun or , as first seen
, from light cast at night from a bulkhead external lamp, so slight
grazing angle of light again.
Both these walls must be mmore than 70 years old.

On 17/01/2015 18:28, N_Cook wrote:
Regular dimensions and flat parallel faces except one, a header. Used
for decorative purposes in header-bond work. So not
malformed/kiln-rejects , perhaps single-part moulding rather than 2-part
moulding, relying on shrinkage for mould release, prior to firing. As
that face , only, is slightly convex , like part of the surface of a
sphere about the size of a space-hopper perhaps. Not bullnose header or
radial header, convex header googles nothing sensible.

Have a look he

http://www.ibstock.com/pdfs/portfoli...cialshapes.pdf

I couldn't see anything as subtle as the picture you linked to. I am
sure I have seen something like their cownose used for infill panels
between massive piers, buttresses, etc., such as you get in parts of the
London Underground. With a half-width offset they produced a strong
bumpy pattern.

They also list radial headers but, again, they look more pronounced.
Also, they are intended for curved walls and built in the flat would
have excessive gaps.

I think yours are simply bricks with slightly curved ends! Such things
might occur with specific clays which exhibit uneven shrinkage, I wonder
if excessively wet clay could have made for that effect? I think you
said 75 years or so - which would correspond to start of WWII. Maybe
poorer quality because of that? (Inexperienced workers, attempts at
economy, etc.)

--
Rod

On 18/01/15 08:48, N_Cook wrote:
On 18/01/2015 08:18, harryagain wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size
of a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

ISTR I saw bricks like that years ago.
No apparent reason for them, I assumed they were just cheap bricks and
they
were that shape due to the (dodgy) manufacturing process/clay they
were made
from.



I think I'm coming round to that opinion. Why make a profile that is so
subtle that you can only see the effect with a glancing sun angle and
even then not that pronounced
http://diverse.4mg.com/cobble-bricks2.jpg
natuaral colour pic, the lower left corner is in shade from a tree, so
dead flat looking. On reveiwing the pics I don't think the cobbling is
that consistent to be deliberate, some seem more "radial" shape of
curvature, on one axis only, and not "sperical"
The other wall is only obvious likewise in angled sun or , as first seen
, from light cast at night from a bulkhead external lamp, so slight
grazing angle of light again.
Both these walls must be mmore than 70 years old.

I think that is the key. They weren't built like that, they have eroded
to that

Or something in the mortar has caused it.


--
Everything you read in newspapers is absolutely true, except for the
rare story of which you happen to have first-hand knowledge. €“ Erwin Knoll

On 18/01/2015 12:02, The Natural Philosopher wrote:
On 18/01/15 08:48, N_Cook wrote:
On 18/01/2015 08:18, harryagain wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not
malformed/kiln-rejects ,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size
of a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

ISTR I saw bricks like that years ago.
No apparent reason for them, I assumed they were just cheap bricks and
they
were that shape due to the (dodgy) manufacturing process/clay they
were made
from.



I think I'm coming round to that opinion. Why make a profile that is so
subtle that you can only see the effect with a glancing sun angle and
even then not that pronounced
http://diverse.4mg.com/cobble-bricks2.jpg
natuaral colour pic, the lower left corner is in shade from a tree, so
dead flat looking. On reveiwing the pics I don't think the cobbling is
that consistent to be deliberate, some seem more "radial" shape of
curvature, on one axis only, and not "sperical"
The other wall is only obvious likewise in angled sun or , as first seen
, from light cast at night from a bulkhead external lamp, so slight
grazing angle of light again.
Both these walls must be mmore than 70 years old.

I think that is the key. They weren't built like that, they have eroded
to that

Or something in the mortar has caused it.



I was hoping no one could put a name to these sorts of bricks. Because I
reckon they are not bricks but undiscovered examples of mathematical
tiles from antiquity, my page on these beauties
www.diverse.4mg.com/math_tiles.htm
The Bugle St, Southampton house and the main front facade of the Kings
Somborne vivcarage, that only the rear elevation is redorded to have them.
That slight bowing is exactly how most of these brick-tiles warp in the
kiln. It seems only one modern day company (the snap-cut tiles, so they
can double as headers and stretchers) knows how to make the exact
flat-plane orthogonal tiles of its mathematical name. I've not been able
to establish what company that is. In antiquity there seems to have been
perhaps only one company that could make them also, I wonder if there
was continuity of knowledge as they have been made , to various extents
over the intervening centuries.

"Weatherlawyer" wrote in message
...
On Saturday, 17 January 2015 20:45:53 UTC, Phil L wrote:
"Weatherlawyer" wrote in message
news:83708c3c-586f-4143-bb82-
Quoins?
Corner stones.


An entire building built of corner stones?

Did you even bother to read any posts in the thread?

There was nothing in the the OP to say that the whole building was made of
quoins although judging from the mettle of your post ...

(There aren't many buildings around these parts built in headers.
When i was 18 I worked in a street in Manchester and the bakery on the
corner was built entirely of headers, pale yellow ones IIRC.
I bought a chicken and mushroom pie from there one day and there was a fly
embeded in the pastry)

...even you might have noticed that such a thing was not impossible if
somewhat unusual. However given their calibre (see example above) one
would be a fool to force one's self to read the gamut of fly ridden
stories such as your.


So that's a no then.

"The Natural Philosopher" wrote in message
...
On 18/01/15 08:48, N_Cook wrote:
On 18/01/2015 08:18, harryagain wrote:
"N_Cook" wrote in message
...
Regular dimensions and flat parallel faces except one, a header. Used
for
decorative purposes in header-bond work. So not malformed/kiln-rejects
,
perhaps single-part moulding rather than 2-part moulding, relying on
shrinkage for mould release, prior to firing. As that face , only, is
slightly convex , like part of the surface of a sphere about the size
of a
space-hopper perhaps. Not bullnose header or radial header, convex
header
googles nothing sensible.

ISTR I saw bricks like that years ago.
No apparent reason for them, I assumed they were just cheap bricks and
they
were that shape due to the (dodgy) manufacturing process/clay they
were made
from.



I think I'm coming round to that opinion. Why make a profile that is so
subtle that you can only see the effect with a glancing sun angle and
even then not that pronounced
http://diverse.4mg.com/cobble-bricks2.jpg
natuaral colour pic, the lower left corner is in shade from a tree, so
dead flat looking. On reveiwing the pics I don't think the cobbling is
that consistent to be deliberate, some seem more "radial" shape of
curvature, on one axis only, and not "sperical"
The other wall is only obvious likewise in angled sun or , as first seen
, from light cast at night from a bulkhead external lamp, so slight
grazing angle of light again.
Both these walls must be mmore than 70 years old.

I think that is the key. They weren't built like that, they have eroded to
that

Never seen that happen with any brick work and youd
see the mortar proud if that had happened and you dont.

Or something in the mortar has caused it.

Ditto.

There is a British Standard list of defined specials ... majority are
shown in this pdf ..you can grab it on my dropbox:
https://www.dropbox.com/s/u25twh7wiv...cials.pdf?dl=0

I had never heard of Mathematical Brick until I read this thread. Still
(after Googling) can't understand the origin of the name.

On 19/01/2015 10:00, DerbyBorn wrote:
I had never heard of Mathematical Brick until I read this thread. Still
(after Googling) can't understand the origin of the name.


Its lost in history, it was the term used in late 18C in their hayday. I
originally had the impression they were 2 or more "bricks" as 1 tile
requiring a 3D manipulation of over and under , overlapping and
interlocking at the fixing stage, so topology branch of maths.
But over my researches I've never seen more than 1 tile , excluding
tiles with a return face for external angles, simulating 2 surfaces of 1
brick .
The 18C useage of mathematical meant precision rather than requiring 3
dimensional geometry or equations and such

N_Cook wrote in :

On 19/01/2015 10:00, DerbyBorn wrote:
I had never heard of Mathematical Brick until I read this thread. Still
(after Googling) can't understand the origin of the name.


Its lost in history, it was the term used in late 18C in their hayday. I
originally had the impression they were 2 or more "bricks" as 1 tile
requiring a 3D manipulation of over and under , overlapping and
interlocking at the fixing stage, so topology branch of maths.
But over my researches I've never seen more than 1 tile , excluding
tiles with a return face for external angles, simulating 2 surfaces of 1
brick .
The 18C useage of mathematical meant precision rather than requiring 3
dimensional geometry or equations and such


Thanks - interesting.

On 19/01/2015 10:25, N_Cook wrote:
On 19/01/2015 10:00, DerbyBorn wrote:
I had never heard of Mathematical Brick until I read this thread. Still
(after Googling) can't understand the origin of the name.


Its lost in history, it was the term used in late 18C in their hayday. I
originally had the impression they were 2 or more "bricks" as 1 tile
requiring a 3D manipulation of over and under , overlapping and
interlocking at the fixing stage, so topology branch of maths.
But over my researches I've never seen more than 1 tile , excluding
tiles with a return face for external angles, simulating 2 surfaces of 1
brick .
The 18C useage of mathematical meant precision rather than requiring 3
dimensional geometry or equations and such

For "I've never seen more than 1 tile" read "I've never seen more than 1
"brick" per tile".

I've seen suggestions of 2 bricks per tile because a 2 brick repeat
irregularity in a number of surviving walls but not one of them where
one is fully slipped or exposed.
Perhaps the Alec Clifton Taylor , 1981 program showing them in Lewis,
showed a multibrick example, and its lodged in my head but Ihave no
definite recollection