As a chemist/biochemist, I thought I might toss in a very basic comment on the "heaviness" question that I didn't notice in the discussion as yet.  If brass may be viewed as a replacement of copper by zinc, then the weight of a vessel should be related to the atomic weight of the elements.  Copper has an atomic weight of 63.54.  Zinc's atomic weight is almost the same at 65.37.  I would expect that replacing copper with zinc could make a vessel a little bit heavier, but the increase would be insignificant, especially if the alloy is predominantly copper. This is probably an oversimplification because I am not taking into account the changes in physical properties of the brass alloy.  
Allen

-----Original Message-----
>From: Michael Bathrick <[log in to unmask]>
>Sent: Sep 9, 2013 12:37 PM
>To: [log in to unmask]
>Subject: Re: Brass vs. copper kettles
>
>Post 1850, many kettles were thin, spun metal buckets (thin being 
>relative to size of the bucket/kettle) as opposed to hammered.
>
>Mike
>
>On 9/9/2013 11:01 AM, Branstner, Mark C wrote:
>> Thanks Misty!
>>
>> So ... It is your position that "copper kettles" and "brass kettles" would
>> essentially follow the same physical form, I.e., thin, hand-hammered or
>> perhaps machine-hammered metal - probably with some sort of riveted, lug
>> handle. The only real difference would be the physical composition of the
>> metal, reddish copper or yellowish brass.
>>
>> Basically, I should throw out my mental picture of heavy, cast brass
>> kettles?
>>
>> Mark
>>
>> ___________________________________
>>
>> Mark C. Branstner, RPA, AARP
>> Senior Historical Archaeologist
>>
>> Illinois State Archaeological Survey
>> Prairie Research Institute
>> University of Illinois at Urbana-Champaign
>> 209 Nuclear Physics Lab, MC-571
>> 23 East Stadium Drive
>> Champaign, IL 61820
>>
>> Phone: 217.244.0892
>> Fax: 217.244.7458
>> Cell: 217.549.6990
>> [log in to unmask]
>>
>> "The difference between genius and idiocy? Genius has its limits."  --
>> Albert Einstein
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> On 9/9/13 9:53 AM, "Misty Jackson" <[log in to unmask]> wrote:
>>
>>> Mark,
>>>
>>> Copper kettles were made of copper, and brass kettles were made of brass,
>>> generally speaking. Copper was the common material prior to the 18th c.,
>>> but given that it was more expensive, zinc was added more commonly in the
>>> 18th c. to reduce the cost, thus making brass. Depending on how much zinc
>>> you add, the material can still look very copper-like, which was probably
>>> something traders wanted to retain so their clients would buy it.
>>> Therefore you can¹t necessarily tell by looking whether you have pure
>>> copper kettles (reddish) or one that looks that way but had some zinc
>>> added to make it less expensive. When more zinc is added, then you
>>> achieve the gold appearance associated with brass. The Montreal merchants
>>> sometimes specified whether they were selling copper or brass kettles.
>>> They may not have known themselves whether the copper-looking ones had
>>> some zinc in them, though the price may have been an indicator.
>>>
>>> So there is a shift over time in what to expect in material, rather than
>>> any shift in lug form being linked with the material. The square ³dog
>>> eared² French lugs show up in the 17th and 18th c. and aren¹t linked
>>> specifically with true copper vs. copper-looking vs. brass. Holland
>>> kettles, if made in England (in the 18th c. England had Dutch tradesmen
>>> come over to make kettles for them) also have the same issue since the
>>> lugs tend to be iron but would have experienced the same general shift
>>> through time in the material used for the body. The bodies of the older
>>> kettles (16th c., early 17th c.?) from what I¹ve observed are often
>>> rounded, but I saw a straight sided, flat bottomed one in a museum in The
>>> Netherlands, too. The designs of the bodies appeared to be linked to time
>>> period and nationality, rather than materials, too.
>>>
>>> You can use a scratch test, though some may frown on this. I tried it on
>>> a scrap that looked like copper. The scratch reveals golden color if the
>>> material is actually brass.
>>>
>>> I covered this in my dissertaion, specifically in one of the appendices
>>> under the entry for kettles. It¹s titled :CLASSIFICATIONS BY HISTORICAL
>>> ARCHAEOLOGISTS AND EIGHTEENTH CENTURY MONTREAL MERCHANTS AND MILITARY
>>> PERSONNEL IN NEW FRANCE: EMIC AND ETIC APPROACHES. And of course you can
>>> look at the bib for my sources.
>>>
>>> Misty
>>>
>>>
>>> Misty Jackson, Ph.D., RPA
>>> Arbre Croche Cultural Resources
>>> 214 South Main Street
>>> Leslie, Michigan 49251
>>>
>>>
>>> On Sep 9, 2013, at 10:08 AM, Branstner, Mark C wrote:
>>>
>>>> Ok, question of the day Š People refer in a very off-hand way about
>>>> copper kettles or brass kettles, and use the terms interchangeably Š
>>>>
>>>> But is there is fact a difference? I understand copper pots made of
>>>> very thin copper stock with riveted bail lugs that were often
>>>> secondarily cut-up for tinkling cones, etc.
>>>>
>>>> On the other hand, when I think of brass kettles, I think of something
>>>> heavier, probably cast, and certainly less portable from a weight
>>>> perspective.
>>>>
>>>> So Š Are copper kettles different than brass kettles, or are they
>>>> essentially identical but made different materials, or are some folks
>>>> just incorrectly describing copper kettles as being made of brass?
>>>>
>>>> Probably all of the above, but I would love to hear some opinions, or
>>>> handy links.
>>>>
>>>> Thanks in advance,
>>>>
>>>> mark
>>>>
>>>> ___________________________________
>>>>
>>>>
>>>> Mark C. Branstner, RPA, AARP
>>>>
>>>> Senior Historical Archaeologist
>>>>
>>>>
>>>> Illinois State Archaeological Survey
>>>>
>>>> Prairie Research Institute
>>>>
>>>> University of Illinois at Urbana-Champaign
>>>>
>>>> 209 Nuclear Physics Lab, MC-571
>>>>
>>>> 23 East Stadium Drive
>>>>
>>>> Champaign, IL 61820
>>>>
>>>>
>>>> Phone: 217.244.0892
>>>>
>>>> Fax: 217.244.7458
>>>>
>>>> Cell: 217.549.6990
>>>>
>>>> [log in to unmask]
>>>>
>>>>
>>>> "The difference between genius and idiocy? Genius has its limits."  --
>>>> Albert Einstein
>>>>