DOI Seite / Zitierlink:
https://doi.org/10.11588/diglit.11365#0035
THE MANUFACTURES.
25
bone among the earth. The mean diameters of the
circles are 430 and 516 inches, and 1215 and 1343
inches.
50. On examining the dimensions of the buildings
it seems that a usual plan was to fix on some number
of cubits for the hall, and sometimes for the whole
house ; then the chambers were partly determined by
even numbers of cubits, and partly by resultant
quantities involving the thickness of the walls.
The bricks varied in size ; but they, were never even
divisions of the cubit, so as to make the walls work
in with the cubit. From 12 to 15 inches long, and
half as wide was the usual size for bricks. The
varieties of the cubit that appear to have been used
are, in inches :
20 • 2
No.
I
20-68
No. 18
20-42
>)
2
20-70
5
20-43
6
20-70
33 n
20-56
j >
14
20-72
,. 8
20-58
?>
17
20-76
33 10
20" 60
j>
19
20-77
„ 7
20"62
33
16
20-79
.3 15
20-67
33
21
20-81
» 9
20-67
J3
4
21-03
„ 13
The middle value of these is 20 "68 ; which will not
be affected by omitting the first and last, as being
doubtfully far from the proper value. The middle
variation from the middle value is -09 ; and as there
are sixteen examples the probable error of the middle
value will be this ~ 5, which yields 20 ■ 68
inches ± -03 for the mean cubit used at this place
and period. The early cubit of 20-63 had therefore
been lengthened to the value of 20*68 by the XVIIIth
dynasty, and it lengthened slightly more on reaching
Roman times.
CHAPTER IV.
THE MANUFACTURES.
51. The new capital of Akhenaten needed a large
amount of decorative work, and suitable factories
sprung up to supply the material. The glazes and
glass were the two principal manufactures, and in
those lines under the impulse of the new art a variety
and a brilliancy was attained, which was never
reached in earlier or later times. So far as the use
of glazes is possible, this period shews the highest
degree of success, and the greatest variety of appli-
cation.
Fortunately the sites of three or four glass fac-
tories, and two large glazing works, were discovered ;
and though the actual work-rooms had almost van-
ished, the waste heaps were full of fragments which
shewed the methods employed : moreover the waste
heaps of the palace, as we have mentioned in Chap. II,
contained hundreds of pieces of glass vases which
illustrate the finished objects.
We can therefore now trace almost every stage and
detail of the mode of manufacture ; and in this
chapter we shall follow the course of the processes
employed for both glass and glazes.
52. We are already familiar with the frits made by
the Egyptians, from the Xllth dynasty onward, for
colouring purposes. These have been carefully
analyzed and remade by Dr. Russell ; and we know
that the components were silica, lime, alkaline car-
bonates, and copper carbonate varying from 3 per
cent, in delicate greenish blue, up to 20 per cent, in
rich purple blue (see " Medum," p. 44). The green
tints are always produced if iron be present ; and it
is difficult, if not impossible, to obtain silica from
sand without the iron in it preventing the blues being
produced.
One of the first requisites therefore is to obtain the
elements of the mixture free from iron. How this
could be done was quite unknown until I picked up a
piece of a pan of frit, which had been broken in the
furnace and rejected, before it was combined. This
shewed clearly throughout the mass the chips of white
silica; and from their forms they were clearly the
result of crushing the quartz pebbles which are to be
found on the surface of the desert, having been rolled
down by the Nile from the disintegration of primitive
rocks further south. The half-formed frit was of a
fine violet colour, proving the freedom of it from iron.
The lime, alkali, and copper had combined already,
and the silica was in course of solution and combina-
tion with the alkali and lime, half dissolved like sugar
stirred into a pudding. The carbonic acid in the lime
and alkali had been partly liberated by the dissolved
silica, and had raised the mass into a spongy paste.
With longer continued heating the silica in ordinary
samples has entirely disappeared, and formed a
mixture of more or less fusible silicates. These
made a pasty mass, when kept at the temperature
required to produce the fine colours ; and this mass
was then moulded into pats, and toasted in the
furnace until the desired tint was reached by the
requisite time and heat ; and a soft crystalline, porous,
friable cake of colour was produced.
E
/
25
bone among the earth. The mean diameters of the
circles are 430 and 516 inches, and 1215 and 1343
inches.
50. On examining the dimensions of the buildings
it seems that a usual plan was to fix on some number
of cubits for the hall, and sometimes for the whole
house ; then the chambers were partly determined by
even numbers of cubits, and partly by resultant
quantities involving the thickness of the walls.
The bricks varied in size ; but they, were never even
divisions of the cubit, so as to make the walls work
in with the cubit. From 12 to 15 inches long, and
half as wide was the usual size for bricks. The
varieties of the cubit that appear to have been used
are, in inches :
20 • 2
No.
I
20-68
No. 18
20-42
>)
2
20-70
5
20-43
6
20-70
33 n
20-56
j >
14
20-72
,. 8
20-58
?>
17
20-76
33 10
20" 60
j>
19
20-77
„ 7
20"62
33
16
20-79
.3 15
20-67
33
21
20-81
» 9
20-67
J3
4
21-03
„ 13
The middle value of these is 20 "68 ; which will not
be affected by omitting the first and last, as being
doubtfully far from the proper value. The middle
variation from the middle value is -09 ; and as there
are sixteen examples the probable error of the middle
value will be this ~ 5, which yields 20 ■ 68
inches ± -03 for the mean cubit used at this place
and period. The early cubit of 20-63 had therefore
been lengthened to the value of 20*68 by the XVIIIth
dynasty, and it lengthened slightly more on reaching
Roman times.
CHAPTER IV.
THE MANUFACTURES.
51. The new capital of Akhenaten needed a large
amount of decorative work, and suitable factories
sprung up to supply the material. The glazes and
glass were the two principal manufactures, and in
those lines under the impulse of the new art a variety
and a brilliancy was attained, which was never
reached in earlier or later times. So far as the use
of glazes is possible, this period shews the highest
degree of success, and the greatest variety of appli-
cation.
Fortunately the sites of three or four glass fac-
tories, and two large glazing works, were discovered ;
and though the actual work-rooms had almost van-
ished, the waste heaps were full of fragments which
shewed the methods employed : moreover the waste
heaps of the palace, as we have mentioned in Chap. II,
contained hundreds of pieces of glass vases which
illustrate the finished objects.
We can therefore now trace almost every stage and
detail of the mode of manufacture ; and in this
chapter we shall follow the course of the processes
employed for both glass and glazes.
52. We are already familiar with the frits made by
the Egyptians, from the Xllth dynasty onward, for
colouring purposes. These have been carefully
analyzed and remade by Dr. Russell ; and we know
that the components were silica, lime, alkaline car-
bonates, and copper carbonate varying from 3 per
cent, in delicate greenish blue, up to 20 per cent, in
rich purple blue (see " Medum," p. 44). The green
tints are always produced if iron be present ; and it
is difficult, if not impossible, to obtain silica from
sand without the iron in it preventing the blues being
produced.
One of the first requisites therefore is to obtain the
elements of the mixture free from iron. How this
could be done was quite unknown until I picked up a
piece of a pan of frit, which had been broken in the
furnace and rejected, before it was combined. This
shewed clearly throughout the mass the chips of white
silica; and from their forms they were clearly the
result of crushing the quartz pebbles which are to be
found on the surface of the desert, having been rolled
down by the Nile from the disintegration of primitive
rocks further south. The half-formed frit was of a
fine violet colour, proving the freedom of it from iron.
The lime, alkali, and copper had combined already,
and the silica was in course of solution and combina-
tion with the alkali and lime, half dissolved like sugar
stirred into a pudding. The carbonic acid in the lime
and alkali had been partly liberated by the dissolved
silica, and had raised the mass into a spongy paste.
With longer continued heating the silica in ordinary
samples has entirely disappeared, and formed a
mixture of more or less fusible silicates. These
made a pasty mass, when kept at the temperature
required to produce the fine colours ; and this mass
was then moulded into pats, and toasted in the
furnace until the desired tint was reached by the
requisite time and heat ; and a soft crystalline, porous,
friable cake of colour was produced.
E
/