Class Notes 12 Sept 2014 Casting in Breadmolds


- Casting Sulfur in Snow (Sulfur Melts at 239.4 F)
- 29r: Stucco and Bread Molding
- 140v: Sulfur; word for bread 'pith' is slightly different--acc. to Cotgrave, miette is the crumbs and fragments of bread
- 156r: Bread molding as time-saver.
- Bread Molding in Platt (p.58) -- fat of Bacon, strained.
- Polarity of fat and lean. Unctuous. Theophrastus on soils. Pigments described as fat or lean.
- Biringucio: "All earths...fat or lean..." (218, Book 6)
- Temper: to mix.
- pp. 62-63, Cellini, on Casting Seals
-"Empreinte," article by M. le Chevalier de Jaucourt in Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers, etc., eds. Denis Diderot and Jean le Rond d'Alembert. University of Chicago: ARTFL Encyclopédie Project (Spring 2013 Edition), Robert Morrissey (ed), http://encyclopedie.uchicago.edu/. First Paris edition, 1751-1772.
Detailed bread molding instructions starting from the 3rd paragraph of page 596: French transcription here, and image of original page here.


- Wax -- Theophilus: 132-138, 165-182 - lost wax casting. Mix w/ finely ground tile.
-- Cellini: gilding; add lead (p.72)
-- Add turpentine -> makes wax softer (Ms. Fr. 640, 109r)
-- Mixing wax with resin to make harder and firmer (source?)
-- Beeswax candles expensive; tallow candles probably used.
-- Platt: p.59 (1594 edn., Book 4) - Coloring wax with coal, etc.

Properties of Bread: Malleability; Cheap; Readily available; Easily scaled, sized; Comes with own frame; Takes different heats; Can make a mold quickly; Will not crack upon quick drying; Lends self to experimentation

Class Notes 26 Sept 2014

by Jenny Boulboullé
Location: Chandler Lab 260

9.20 AM (weather conditions: sunny, not too hot outside)

Beeswax pouring with self-made bread molds

For materials and equipments see video/photograph documentation (reference signature for photo/videomaterial needs still to be filled in here. Following up the thoughtful recommendations made by our guest lecturer, Jeffrey Lancaster, on Lab notes during our last session, we had an animated disucssion about a proper reference system that ties photographs, texts and objects together... to be continued)

The beeswax was heated until fluid on single burner, using variable medium temperature.
We made small lips into paper coffee cups
We first poured the beeswax into paper coffee cups;
then we carefully filled the bread molds with beeswax using the paper coffee cups.
We poured the beeswax gently and slowly.

Some samples did not fill up very well, because they had cracks or open spaces through which the wax leaked out.
In some cases we tried to fill up the cracks with wax and poured more wax into the mold, and that seemed to work fine for some molds.

We had some good examples where the wax casts came out very well and quite easily from the bread molds, but in all cases the pith stuck to the wax and had to be peeled off carefully.There were some good results with detailed surface impressions (see photographic documentation).
We did not have access yet to warm water in the lab, so we took our casts home to further clean them up there.

Note: Our molds had been already made a week or longer ago. The molds therefore had been probably shrinking and curling on the edges.

Class Notes 3 October 2014

by Jenny
PERHAPS JOEL CAN FILL IN ON THESE NOTES FROM HIS EXPERIENCE IN MAKING THE MIXES? AND OTHERS ON THEIR EXPERIENCES OF HOW THEIR CASTS CAME OUT, LOOKED AND FELT AND WHETHER THEY NOTICED DIFFERENCES WHEN USING DIFFERENT BREAD MOLDS?

We experimented with 3 fillings

Pure bees wax
because of the colour of the wax you could not see the details very well, but it when cleaining under water one could see very detailed impressions on the little pill bottle
bees wax slightly more transparant, diffuses the light

Mixtures of wax and tallow 50/50
tallow and wax, objects burst and cracked, MS says to add tallow to make it softer, we probably added too much wax

Dinosaur cast (add pictures and/or references to pictures)
The wax/tallow mixture popped out beautifully, without sticking to the breadmold at all. It has a detailed impression and feels quite soft and fatty. The breadmold could even be reused for sulfur cast (see below)

Pure sulfur
much easier to get out of mold, had the most detailed impressions

Dinosaur cast (add pictures/reference sign)
The sulfur cast broke when I tried to get it out of the breadmold, its is much harder and more brittle than the wax/tallow. The impressions seem even more detailed and pronounced than the wax/tallow, but that could also be due to the different colours, the soft white yellow one showing looking less pronounced than the greenish yellow of the sulfur.

On sulfur and wax
It is still a mystery how the bees wax works with sulfur, sulfur melts at much higher temperature than sulfur at 240 degrees fahrenheit and it did not mix in our experiment with wax;
In the MS it says you pass sulfur "through" wax p139v , in our experiment we kept two seperate liquids they did not mix, we tried to cast it, but also in the mold they separated.


From MS tl_p140r
<ab id="p139v_b1c">
Make the first casting twice as large as other molds. And if, in the first casting, your work fills with bubbles and in so doing does not come out neatly, it’s all the same, because you have to face the fact that the three or four first do not readily come out well. Firstly, you will know whether there are a few barbs that keep it from stripping well. And you will remove them if, on their own, they do not remove themselves in the two or three first castings. And the more that you cast, the more you will do it neatly. And your mold will serve you more than one hundred times if it Is well governed. But it is good to soak it one night or one day before casting so that it be well soaked. The same must be done for fruits made from sugar. This wax is very soft & friendly & pliant, like copper. And if it is hard [this is] because of sulfur, which makes it melt more easily than than other [wax], so much that you can see evidence on a hot slate. And the sulfur that you put inside will be found the second time that you melt it, [as] cracks on the bottom. Having in this way passed through wax, it will not catch fire at all when put to a candle. And in this case, I believe that it will cast quite the medal [illegible]. One uses the same wax in place of varnish to [illegible].</ab>

tl p139v
__http://gallica.bnf.fr/ark:/12148/btv1b9059316c/f285.item__


<ab id=“p139r_b1b”> are made of earth or blades of copper, or iron, or wood covered with white iron, in order to bury more easily these aforementioned molds between the thin sheets of copper, estric or one of iron.</ab>

<title id=“p139v_a1”>Casting wax to mold an animal that one has not got</title>

<ab id=“p139v_b1a”>Take some white wax which is much more appropriate for this kind of work than anything else, because it is much firmer and does not leave as much filth, as much as you need to cast the animal that you propose, and no more. And [take] a half quantity of ground coal and neatly sieved through a cloth or coal sleeve, using it to give some color to your wax, that would otherwise be transparent and you will not be able to see your lines as clearly. Put your wax on the coal fire to melt. And when it is well-melted and well-liquified, take a full eared-porringer of melted wax, [and] as much sulphur as the amount of a large pulverized walnut. Melt all of over a slow fire and when it is melted, do not leave it on the fire because it will become too hot. But take it off and keep stirring it with a little stick and when it has finished bubbling and is as liquified as water, cast it into the wax that you will have previously removed from the fire. And mix and stir both of the them so that they join together. After stir in little by little while continuously mixing, the charcoal that has been repeatedly ground, and in this way it will be very well incorporated. This is how you will know that your wax has gone beyond its ideal heating point, it will release no more smoke, it will start to have lines appearing on the side and not in the middle, and those lines will be close to each other. If you cast too hot, you will not be able to separate your wax from your mold and it would stick to the cast. When it is at the right state, stir it with a little stick so that the pulverized charcoal is well mixed in and has not fallen to the bottom of the mixture. And in this way, throw it in your mold bit by bit and not in one go, because wax is not runny.</ab>

<note id=“p139v_c1a”>This black sulphured wax is for fashioning round figures that do not come out of the mold. And they need to be burned in the moule au noyau rather than be opened like the ones that have something jutting out or an intertwining of legs and arms. And this wax, thanks to the sulphur, will melt with little heat and leave without leaving any filth. If by some misfortune the crushed charcoal remains in ashes, when you open the mold and blow on it, it will come clean.</note>

<note id=“p139v_c1b”>To make wax serpents or other things to affix to candles, it is necessary to cast them with esbaucher wax of all colors.</note>


discussion on smoking wax, we have not experimented with adding charcoal yet.

we discuss how to hold the mold parts together (some students had put books on their casting objects, in MS is a section on clamps)
151r on clamps and lute
"Lute" - used as a protective shell made of disgusting elements, like hair, mucus, think of the smell of the early modern workshop

Class notes 17 October Discussion on casts made at Ubaldo's


Discussion on workweek with Tonny on sand mold making and of silver and tin casts made at Ubaldo’s Forge on 16 October

On the quality of impressions in sand molds

- two problems due to our use of pure bees wax and the quality of our sand

harder sharper patterns would work better for detailed impressions in the sand, e.g. the coin we pressed in from Jonah.
Our control cast from commercial delft sand
We can observe flashing
Other method to struck coins
Ancient method
Metal is made soft by annealing: heating up to a temperature that the microstructures of the crystals are in their most relaxed state.
A temperature almost getting to red glow in which the metal structure is relaxing again. When you hammer or work on a metal it will get stressed, e.g. silver it is getting harder and harder, eventually cracking (point of no return). annealing is softening up and relaxing the metal again.

Pickle: an acid to clean of the surface oxide layers, it has no protective function for the future, you use it on silver, but not on tin

10% Sulfuric acid in water
silver comes out wonderful white like satin

Flux: the flux binds with the oxide layer (the scum on the surface) and cleans it. And at the same time it is providing a protective layer for future oxidation, if you would not use it the metal will get much oxidation, it is also a preparatory agent for soldering, because the metals would not anneal if they is any oxide on their surface.
You use it when we melting metal and you also use at when you are soldering to keep it clean while you work with the flame.

we added rosin, you could also use borax as a flux
Earliest fluxes, you could also use table salt in paste form
Borax is the most common one
More resin type fluxes, more greasy type of fluxes

Sal ammoniac
We used it in our sand, we do not why it is aided. We assume that it might also have a cleaning agent function. You want to get a very clean cast.
It will react with the sand, it will solidify and prevent oxidation (?).



Step by step discussion of the recipe 118v


Molding and Casting experiments. 10.16.14
<title id=”p118v_a1”>Excellent sand</title>
<ab id=”p118v_b1a”>Get some of the same sand, the finest that you can, for covering the medal.</ab>
<ab id=”p118v_b1b”>For the best [result], it is necessary to take sand already used in the core before using it in the box mold, until it can no longer be taken out.</ab>
<title id=”p118v_b2”>Casting in a box mold</title>
<ab id=”p118v_b2a”>The same sand which has been used in composed heated cores, i.e. of plaster, brick and feather alum, is excellent for casting in box molds, and I have tried it as follows. I crushed the pieces which had come out of core molds in a mortar, pestling slowly, because this sand is very soft. I did not pass it through a sieve, because the feather alum mixed in, which makes it bind together, would not pass through. But I did refine upon marble what seemed to me too coarse, and having thus prepared it, I moistened it with the sal ammoniac water made of sal ammoniac the size of two walnuts, in a bottle of common water the size of a bottle in which one boils ground barley, or in a good pot of water. You should find the water fairly salty. I mixed in half a glass of sal ammoniac two silver spoonfuls of spirits. Having thus moistened the sand in order to give it a nice hold, though it still came apart easily, I sprinkled my medal with charcoal pulverized with a file to remove the oil fat, and all other fat. One must avoid these, since they hinder good stripping. I blew on the medal and molded it, and with the female part of the box mold full, I marked and made a line on the back and side of the medal, and on the nearby sand as well. In order that the second box mold take the imprint thereupon to indicate the place for making the cast, I uncovered the contour of the medal and pounced the whole side with pulverized carbon, and then I filled the male part with sand. I separated the box mold and did not strike the corners of the medal to make it strip, since that cracks the sand and makes it come apart. But I did strike the back of the box mold, holding the place of the medal on the bottom, and it molded very cleanly. If it hadn’t stripped thus, I would have waited to remove it until the box molds had been dried out over heat. I lit a row of charcoal between two little trivets of iron in the form that you see [viz. image id=”p118_d2” in the left margin], and put the back of the box molds thereupon, and the imprint on top, since in this way, they dry out slowly. And if, by chance, they should crack from being too moistened, it’s on the back that they take the harshest heat, and the imprint remains safe and whole.
<ab id=”p118v_b2b”> When I saw that they did not smoke anymore, & scratching the back & the front of the casting & having found that they are rough & firm & hard on both sides, which is a good sign of their being quite dry, I leave them to cool down. I took some fine tin, one lb., & one ounce of fine & new lead. I melted it in a crucible just until it was a bit red. Being in this way quite hot & ready to cast & no sooner, I smoked every side of my box frame with the smoke of a tallow candle & pressed & cast & everything. I set my box frame, well joined, in the press. I drew my crucible from the fire. I let it sit a bit to quench the redness of the crucible’s bottom. And wanting to cast, I threw in around two or three grains of rosin, and about the measure of a bean of looking-glass tin & blended it & stirred the crucible a little and cast. And the medal came out as neat as the original. I smoked it with the candle & cleaned it with my coat.</ab>
<note id=”p118v_c2a”>For medals and flat things, the true heat of lead and tin. That is when it is melted gently.</note>
<note id=”p118v_c2b”>Note that I filled the box mold before pressing, and did not strike it, but pressed it with the strength of my hands alone, since striking it may distort it. Make sure that your box mold does not move at all, and if you put some moistened sand under it, it will only hold in place more firmly.</note>
<note id=”p118v_c2c”>Make a cast that is not too thick, as not to weigh the medal down, but cast wide enough over the medal that it covers the third part. Do not forget the vents.</note>
<note id=”p118v_c2d”>Drying box molds means removing their dampness, so that they do not smoke any longer, though they be very hot.</note>
<note id=”p118v_c2e”>To heat is to redden the box mold, which is done for gold and for silver.</note>
<note id=”p118v_c2f”>Always cast through the foot of the medal because the head, which is lower, will come out better, and make the casting somewhat long. And when you cast several medals in a large box frame, they will come out better.</note>

119r: casting the above medal in tin
<title id=”p119r_a1”>Notice about everything above</title>
<ab id=”p119r_b1a”> Good tin is that which is hard as silver & soft nevertheless. If your work is fine, it must be almost all tin & alloyed as is said.</ab>
<ab id=”p119r_b1b”>Looking-glass tin must not be mixed until the instant that you want to cast.</ab>
<ab id=”p119r_b1c”> Nor must the forms be smoked until then.</ab>
<ab id=”p119r_b1d”> If the sand shrinks in the box frame, this means that it must be reheated & turned red on the fire.</ab>
<ab id=”p119r_b1e”>Good sand when moistened does not stick at all to the hand when pressed.</ab>
<ab id=”p119r_b1f”>The perfect sand for the box frame is the asphalt found in Germany, which is soft as wet flour, & almost all the rest are lumpy.
<note id=”p119r_c1a”>Note that the casting must be fine & hardly thick so that it does not work the material at all, & must not exceed the thickness of a grain of wheat taken crossw-wise, likewise for tin that is going to be cast finely. For lead, a little thicker. There is no need to make air vents very large & deep either.</note>
<note id=”p119r_c1b”>The sand that you use à noyau for the said mixture is excellent for a box frame. But in washing, crushing & reheating it several times, its nature will be corrupted & it will no longer be fit to be taken & molded en noyau.</note>
Additional Recipes for molding and casting
Mold
<ab id=”p081v_b4”>It is good to make it with bow wood. Turn it in order to make it homogeneous, as that is important for the casting. Cover the mouth of the frame with clay or sand, so that the molten metal, copper or lead, do not touch at all the iron or latten of the frame, because it would turn it sour, and make it filled with bubbles. Always cast higher than the mold. Pay attention that the cast is not too wide or too deep because the narrowest is the best one. Because when it is large, the weight of the matter which runs breaks and spreads the mold and fills the matter with bubbles. When you have casted, gently hit your frame, so that the matter spreads better. Black lead [de saulmon] of the first melting, works very neatly.</ab>
<ab id=”p085v_b4d”>[or metal] fills with bubbles. Most of all, make sure that the cast is always higher than the molded thing, since the sand swells very often when reheating, even in the middle, and therefore with the molded thing remaining higher than the cast, the metal cannot run easily or at all nor enter at all. Also make sure that the mold & the cast are indeed reheated. Also cast in one go & outside of the wind. And if your medal is really thin, when you want to mold it, put a card, or two or three thicknesses of paper, so that the mold will be lower than the cast. Also cast in the place where your medal is least thick & where the relief is lowest.</ab>
<ab id=”p086v_b1h”>When you mold, do not excessively pound on the medal that is in sand, because that prevents it from being cleanly stripped, and cracks the mold.</ab>


<ab id=”p086v_b1i”>See to it that sand does not go over the edges of the box mold, because if the molded medal is higher than the cast, metal will not easily enter the form. Therefore, always take care that the surface of your cast surpasses the mold in a straight line. To accomplish this, if you wish, put a piece of cardboard of whatever thickness you please on top of the mold.</ab>


<ab id=”p086v_b1j”>To prevent their large casting works from becoming too porous, founders are careful to heat their molds very well. And to know if the molds are heated enough, they tap them with their finger, and if they start ringing like a pot, they are heated enough.</ab>

<ab id=”p086v_b1k”>In order to cast their canons cleanly, they mix with their founder’s earth some fine casting sand, if they can get any.</ab>

comments on some parts of the recipe

"I blew on the medal and molded it, and with the female part of the box mold full, I marked and made a line on the back and side of the medal, and on the nearby sand as well"
This probably means that he draw a light line with a pencil or other device across the medal and sand


"I uncovered the contour of the medal and pounced the whole side with pulverized carbon"
This refers to ‘dusting’ the outer line of the medal, e.g. to clear its contours of any sand.
Pouncing probably means to have charcoal in a small sack of cotton on a stick and then pouncing the powder on to it, which would result in a very fine layer of charcoal dust (we used brushes to brush on the charcoal powder)


DISCUSSION Questions


1) First issue:
We did not use feather alum

Go through MS and look where is he using feather alum.
We saw Gypsum at Ubaldo’s yesterday, its structure seemed similar to it or to talk as Ubaldo’s suggested. we want to find out whether we could alternatively use talk.

2) Mold dampness

Our sand was way too wet
we learned so much by this experience. Jonah’s finely detailed model a very good example of what happens when a cast does not work when the mold is too wet: the silver was poured in, but it steamed so heavily that it did not fill up, but was forcefully flashing into the mold. It actually almost exploded into the sand.

3) What is right temperature to pour?

4) Sieve material
the finer your sand is the bonding you get is better, we need finer sieves. In MS tammy cloth is mentioned, he also mentions making sieves from horse hair

5) Appropriate pots
We could try to find visual evidence of the right size of pots

6) spirits
we could do a control only with tap water to check what sal ammoniak and brandy does.
We want to know sal ammoniak proportions and we need to research whether it reacts with the feather alum that we did not add, so it is difficult to decide now whether it has a function.

7) does author of the MS reuse sand molds?

he does reuses plaster casts, but
Our sand:
Made out of previous molds.

8) Material of the pattern. Is he using a medal metal?
if the sand is intended for metal medals we might have reached a much better result t
The earlier molds were made from sand called grog
Grog is an inert sand silica that is very coarse but very fire resistant. Pamela and Tonny used it for their first molds

9) what are the different materials that he used for sand and more specifically are there contemporary or earlier sources in which oil is used for sand preparations? Tonny could not find yet any pre 19th century sources where oil is used.
Look for properties of the binders
- look for references in the MS
- other sources

10) More experiments on the appropriate heating and drying of the molds
Particular concern on how molds are heated and dried, spent specific attention to that in MS, also made a drawing of iron rods on which the molds have to be placed.


Observations on our sand:
Only later they realized that MS said to use the ground tiles or bricks so the second patch of ground old molds was made from bricks and no grog.

The sand nearer the plaster molds felt different, indicating that the plaster molds sucked up the moist from the sand, because of which the impression also was not very good.

MS he also was using all kind of different core materials composed of brick and feather alum.

Modern sand: has oil in it gets much blacker when smoked before pouring. Our sand was much less blackening, so it might be

General observations:
Many problems he is discussing in the other related passages are all problems we encountered and problems that lie on our table now, the author must have gone through these phases

Developing attention, you learn what to pay attention to.

‘Sprinkling with charcoal to get rid of the oil fat’: where does the fat come from?
To make your pattern less sticky, less adhesive to the sand, charcoal as release agent.
Unctuous as property of fat, introducing something dry to counteract it.
Bringing into balance.
Fat and lean, pre Aristotelian, has to refer to agriculture.
Other system not Aristotelian elements.
To get a 100% clean release.

General observation
Type of attention and receptivity
Humility and receptivity
Two way attention
How we experienced how other molds

Engagement sensitivity
Working with materials, becoming connected to it
Question: is our author a professional who can make a living from his experiments? Is he a scholar or a commercial producers, he is going through the learning process, he seems to be inte
He is concerned with product prices, but that does not have to indicate commercial

Planning for next weeks:

which recipes that annotations should be worked on.
- students choose maximum 3 of recipes as pairs on metal working, anything that has to do with molding, it is not about the metals, it is about the mold,
- try to identify the materials to use and questions what you want to ask about the recipes
- beginning to search recipes that predate manuscript that are similar
- do field notes in pairs
reorganizing:

breadmolding
sandcasting
culinary recipes

Class notes Friday 24 October 2014

by Jenny

See the students research plans under Source Materials: Notes on Annotations – Materials

Emogene and Juliana

Mainly focused on recipes: 85v, 84v and 68r-69r
Process and ingredients seem to be workable
It mentions also elm root identical to inner bark (see Joels mail with notes, below FILL IN)
Looking at a colony of recipes
84 v
researching different binders: magistra, vine, and it also mentions burnt oyster : Donna assumes that this refers to burnt oyster shells, which would yield some sort of lime when heating, e.g. calcimine = reducing sth. to ash, the oyster shells, she can get some.

Calcination/calcine
Interesting to look up more information on calcimine processes
Alchemical meaning, First stage of producing a philosophor’s stone
See 102r for information on vessesl used for calcinations
It makes the matter pulverizable

Ref. Cennini p. 5 mentions calicine

Terpentine and butter are mentioned for mixing with wax
Resin = investigate its property as hardening agent

follow up Ubaldo’s suggestion

Tammy cloth used to sieve: straining cloth now, not clear which material: cotton, linen? Wool, hair?
It has only a physical function not a chemical one

Emily and Jef

145r and 106r

Focus on economical issues
Where in his process is he willing to change things to cut costs
More willing to save on appearance? Durability?

Donna: Palissy interesting source
Databases on early modern
Medieval and early modern database: if you type that into CLIO it will bring it up
85v : thickness of the medal he uses a coin as a measurement

In Cennini on verdigris in Ch. 152
Verdigris speeds up the process

trying some different ways to interact with the material
‘use your bare foot’ perhaps

cuttle fish still used today for gold and silver, lots of material on youtube
he mentions cuttle fish best for

flux = powder to add to encourage metals flow

Biringuccio on flux on p.332/333
Cennini also mentions cuttle fish

How to dry out cuttlefish compare to drying out processes for Sand

Jona and Rozemarijn


Group of recipes

White lead mentioned, but for research into hollow reverse casting technique perhaps not necessary to use it
Rather textual research on white lead

Calcinate vitriol – vitriol either iron or copper sulfide, if supplement of that than it would not contain mercury
96r – casting thin things
We can do calcinated vitriol

Turtle article: she discusses processes, but does not discuss recipes that do that
Biringuccio: p. 329-332 on hollow casting: in translation used the term intalio , but Biringuccio actually uses the word cavo, meaning hollow

p. 86-90 interesting references to sulfur in Biringuccio, he talks about other uses of Sulfur


Diana, Yijun & Michelle

163r

amber gris – its an intestinal decretion that washes up on the beach and hardens, highly aromatic, difficult to purchase, you can buy it in Europe
white amber

assume that both the same, translation not checked over yet,


69r sand molding, ox hove bones: very doable
Tripoli, Donna: can get Tripoli material used for polishing materials, feels like really dense clay, unctuous, used for a wheel impregnated with this very greasy stony material

Jordan & Raymond

3 principal topics


Is it possible to cast things in metal again? Donna: we can probably cast in tin in our lab if the kiln arrives in time.
Joel: if we cannot do in metal we might be able in sulfur
Donna can perhaps make arrangements to cast metal in another studio in nyc

Proceed with metal casting research

Recipe group:
117r
large number of illustrations, better understanding of how flower and herbs are cast, complement research on life casting
thick and fat

Palissy casting a lot of flower,
Imitation practice of fabricating flower as a larger interest
MS mentions daisies, roses,
Two diff recipes for molding roses
It looks like sand casting in a box mold, not clear, because prof. Smith suggested they were all done in plaster casting?
And egg white is also mentioned – connection to other group