1840-O half eagle Broad versus Narrow Mill discussion re-visited
jonruns
Posts: 1,197 ✭✭✭✭✭
A couple of months ago IWantNonCCs started an interesting thread on Broad versus Narrow Mill with regards to an 1840-O half eagle that he owns...
DCarr wrote then:
"The broad mill issues do have a wider-looking rim. They are also slightly larger in overall diameter. When I compared broad mill and normal ("narrow") mill 1840 (Philadelphia) coins side-by-side a few years ago, as I remember, the broad mill coin had fine edge reeding and the narrow mill had the normal coarser edge reeding."
The diameter of the Broad Mill 1840 coins is the same as the 1834-1839 half eagles: 22.5mm
This NEWP passes the large diameter test (NGC recognizes the variety while PCGS does not yet)
Even with my fancy new caliper it is very hard to measure a coin in a plastic holder...I measure my new 1840-O at closer to 22.40 than 22.50...but either way it is wider than 22.0...
However I have given myself a headache trying to see any difference in the reeding...DW says the difference is obvious...but then he is the foremost expert in the field and I am not...
Comments
That is a very difficult way to measure a coin.... certainly close enough for an estimate, but not for accuracy. Are you just trying to establish the difference between the mills? Cheers, RickO
RickO -- I thought you would like that digital caliper if nothing else...
The Broad Mill is a significant rarity...and it would seem like it would be worth putting a few away as some day PCGS might recognize the variety...and there would be an increase in demand...
The dilemma is that it is hard to recognize the difference between Broad vs Narrow with the coin in the slab...and probably 99% of the 1840s that we see at shows and auctions are going to be in a slab...we can't exactly crack out a coin at a dealer's booth just to measure it...then say "no thanks"...
So I was trying to find a way to ascertain Broad vs Narrow for graded coins....and I think the caliper is accurate enough to determine at least that it is greater than 22.0...which means it is Broad...
Here's my example
Sorry, this is misattributed I think based on the raised die lines between IB in Liberty. This coin is Variety 2
Latin American Collection
Is this any help? [From Heritage 2009 February Long Beach, CA Signature US Coin Auction #1122, lot 2707.]
1840-O $5 Broad Mill MS61 NGC. Broad Mill half eagles are perhaps one of the most under-researched areas in U.S. gold coinage. The first widely distributed information about them was published 45 years ago in Walter Breen's Hewitt monograph series on gold coins. In his booklet Varieties of United States Half Eagles 1839-1929, he wrote at length about these pieces:
"Mintage commonly quoted as 30,400. The true figure seems to be 40,120. This includes some 4,620 Broad Mill coins struck from the first dies (January through March 1840) plus 35,500 Narrow Mill coins struck between August 1840 and February 1841 inclusive. This particular division may seem arbitrary but it is completely documented in the Archives. Deliveries:
Jan. .... 1,420 Nov. .... 14,000
Feb. .... 3,000 Dec. .... 5,200
March ... 200 Jan '41 .. 6,300
Aug. .... 8,000 Feb. .... 2,000
The first pair of dies was furnished on Jan. 21, 1840, and they were used for the Broad Mill coins, as the error had not yet been discovered at the Philadelphia Mint. Broad Mill coins exist and are quite rare. The second pair of dies was not sent until May 29. These dies were used for the remaining coinage. ... These dies were not destroyed until Feb. 27, 1841, one reverse being left over. The obverse die of 1840, sent Dec. 21, 1840, was not put into use until the following August."
The next appearance of information about these pieces occurred in 1987 and 1988. Breen mentioned them in his 1988 Complete Encyclopedia (page 531) but incorrectly listed them as 22.5 mm in diameter. In the October 1987 Norweb I catalog, Michael Hodder wrote "An Essay on Coin Diameters." Hodder used the coins in Norweb as a starting point for research on this intriguing subject, but left several questions unanswered for future researchers. What he discovered from measurement of half eagles from 1839 through 1847 is that there are actually three diameter ranges. He stated:
"The measurements can be classified into two categories among the earlier pieces on the list, the so-called 'Narrow Mill' coins, measuring 21.7 mm. or 21.8 mm. When we arrive at 1844-O, the first New Orleans Mint half eagle in the collection (New Orleans Mint issues of 1840-O, 1842-O and 1843-O are not in the collection), we come to a 'new' diameter of 21.9 mm., which we shall call the 'Medium Mill.' ... New Orleans Mint coins studied are from different diameter collars producing 21.9 mm. 'Medium Mill' coins."
With the new NGC holders it is now possible to exactly measure the diameter of a coin even though it is encased. This piece measures 21.9 mm, just as Hodder predicted 21 years ago. The coin is noticeably wider than the Narrow Mill variant, and this is especially noticeable with its wider rims. To date (1/09) this is the only Uncirculated Broad Mill 1840-O five certified by NGC (PCGS does not certify this variant). Only eight others have been graded. When encountered such pieces are usually in much lower grades, most often XF40-45, rarely in AU.
Unlike most 1840-O half eagles, this piece is only minimally abraded. In fact, there are no singularly mentionable marks on either side. This is worthy of note as Doug Winter remarked in his latest O-mint reference: "This date is nearly always seen with very heavily abraded surfaces." Another remarkable feature on this piece is the strength of strike. Again, using Winter as a reference, he notes that Broad Mill pieces are usually weakly struck. Light reddish patina is seen over each side of this otherwise green-gold example.
In theory, a case can be made that this is the rarest New Orleans half eagle. Only nine pieces have been certified, and this is the finest. Specialists will surely take note of this special coin. The question that will undoubtedly go through collectors' minds is, "When will another Broad Mill 1840-O five be available in Uncirculated?"(Registry values: P6) (NGC ID# 25SK, PCGS# 8200)
@RogerB
The coin auction listed is also for a misattributed broad mill. The pictures clearly show the raised lines at IB in Liberty. There are three mill widths. Variety two is larger than variety three but not as big as the broad mill.
Check coinfacts and observe the prevalence of those raised die lines. This variety is quite common and often mistaken for the rare broad mill variety
Latin American Collection
IMHO, all the difficulty with these coins was caused by the use of the word "Mill." When I first researched these coins I thought "mill" referred to the reed count (103-104 vs 132,140). With the edge view holders - a numismatist who has seen many of these coins can tell the difference (fine or course reeds) even if he only has one coin. The diameter is what these coins are judged by. Generally 22.something for the Broad Mill and 21.something for the narrow variety.
A word of caution: New Orleans issues seem to screw up the "normal" pattern of reed count and diameter found for the other mints. More research is necessary.
From the Heritage auction cited by RogerB:
With the new NGC holders it is now possible to exactly measure the diameter of a coin even though it is encased. This piece measures 21.9 mm, just as Hodder predicted 21 years ago.
I don't think that a diameter of 21.9 is a Broad Mill...and I might argue that measuring the diameter of an encased coin isn't so easy...
Just so we're clear...NGC is only measuring the Diameter and labelling as "Large" or "Small"...no mention of "Mill"...
Yep. Didn't check check it, just popped it in to possibly aid discussion.
The collar defines the diameter of a struck coin. Diameter is measured from the tops of reeds. If a collar were cut to the statutory diameter, then reeds cut using a knurling tool, the coin would be too great in diameter. Conversely, if the NO machinist cutting a collar assumed diameter was measured from the rim and allowed for reed depth, then the coin would be too small. (There's extensive info on cutting collars in From Mine to Mint. although the material is from the latter 19th century, not 1830s-40s.) The term "mill" or "milling" has nothing to do with the diameter of a finished coin. The milling or upsetting machine outputs a planchet with upset rims, uniform diameter, and just a little smaller than the collar.
[PS: An accurate measurement cannot be made by "eyeballing" with a coin in a slab. You must take a series of measurements - usually 10 or more - making sure you measure all coins from reed-top to reed-top. When I've seen people measure coins at shows, it makes me cringe.]
+1
Wow!!! Given the complexity in getting an accurate read of Broad vs Narrow Mill and Large vs Small Diameter do you think there will ever be any widespread collector interest in these varieties?