Hamilton grade 990-how many versions

[49stude63]

I picked up two Hamilton grade 990's one a 2 screw version from around 1912 and the other a single screw version from 1915. I think the grade was phased out ~1919 but I wondered how many version there were of the 990 there were, I know of at least 2 based on the number of hold down screws on the wind wheels. I would have to say that either of these movements are some of the nicer looking movements made.

[terry hall]

i will agree based on the winding wheel screw.

but not sure if the dial was changed to three foot before this change or concurrent.

what is listed as changes....

1903... Double roller escapement (but the serial number associated is the first watch in the first run of movements so how can this be a change )

1905.... pallet arbor piviot and escape pinion change from 14 to 15 (assume this is a larger size)

1911... flat bottom train

1912.... round bottom train

1914.... new winding hubs ( could assume this was the screw # change)


maybe someone can explain Flat and Round Bottom Train?



Other Trivia

Sold as movements only until 1911, when offered also as a factory cased example in LOng pendant cases.


16489 to 16490 total production.

196 14K
1346 in GF


55 movements 'in the grey' for private labels, etc

25 movements 'special finish'... Freer, Luckenbach patterns, but others possible.

last ones to finishing room... 1321001 8/30/1918

grade closed out 1919, not in july 1919 price list.

300 complete 990's shipped to Ball, April 1911, May 1911 samples sent to all "the inspectors"

[49stude63]

Terry, that is a good question, round vs flat bottom, that is a new one for me. Ok I guess there are 4 versions since the first version in 1903 would leave me thinking and maybe a little since I thought that was the main difference between the 990 and 992, the 990 started with a DR and the 992 started with a SR and later converted to DR. I will have to toss out the serial numbers when they arrive. I know the 990 had some other features to go with the DR were poised pallet fork and I think it also had GJS where the 992 didn't.
Terry the later 1915 990 is cased in a "Illinois Case Co, Napoleon" long pendant case, warranted 25 years swingout with design work on the back. The earlier 1912 is also long pendant gold (filled probably) case with no indication of brand.

[Don Dahlberg]

I believe that flat and round bottom train refers to the rounding of the spokes on the train wheels.

Don

[Tom McIntyre]

Spoke treatment sounds reasonable. I have not examined the Hamiltons, but Elgin used half round, round and flat spokes. I have heared the half round referred to as "coined" spokes (or crossings) but I don't have a reference for that. I have always thought it meant they were die struck to get the round appearance.

[terry hall]

could be the spokes instead of the tooth form...

may be difficult to narrow down, either most likely would have required a die change.

flat bottom listed as serial point 839701
and round as serial point 850301

time for someone to 'stare and compare'


I also believe the 990 started as double roller, that is why i commented as above. The serial point shown is the first watch in the first run...

1903... Double roller escapement (but the serial number associated is the first watch in the first run of movements so how can this be a change )

[49stude63]

I will do a "stare/compare" when they show up, which should be early next week. When I add the serial numbers I will comment what obvious differences that I see other the the number of screws holding the wind wheel on.

[Joe Kendall]

I just checked my 990. It is from the first run, SN 302052. All the wheels in the gear train have round spokes. Round bottom/flat bottom must refer to something else, not the spokes.

Joe

[49stude63]

I figured one of the Illinois experts could give a definitive answer to this flat vs round bottom comment. Both 990's that I picked up would fall into the "round bottom" group.

[LTaupier]

Would the two movements, unmarked and the marked 990 be considered two different versions?

Len

[49stude63]

If I am not mistaken some of the earlier 990's and 992's were unmarked for a short time, hopefully no one hurts me too badly if I am wrong but seems I remember that was indeed the case in the early serial numbers that they were not marked. Geez these 990's are eye-candy on steroids, the first one came today the earlier 2 screw wind wheel version (1912) sn 850,719 and the movement is very pristine, really have to look hard to see any markings. DS dial with a hairline at the 1-2 position and one at the 4-5 position, with a bit of an edge chip at the set lever but very presentable and with some polident action the hairlines should wave bye bye without a loupe, the hands are spade in very good condition.

[Jerry Freedman]

My 990 #302212 is not marked.

[49stude63]

Len I would consider a marked and unmarked to be two versions, Elgin would do that with some movements that could be marked Father Time, BWR etc so in this case both are unique, one marked the other unmarked.

[beta21]

The flat or round bottom train remark most probably refers to the tooth shape of the pinions, the "leaves". "Flat bottom" has square corners at the leaf bottoms, while the "round" obviously has rounded. The latter is more modern, easier to manufacture and gives stronger leaves less liable to breakage, while the former have a nicer appearance and give a nice thin polished line at the undercut, which is impossible with the rounded variety. Nowadays rounded are used exclusively.