A Guide to Illinois Watch Co. size 12 watches, Grade 401.
Run.
Date
From
To
Total
H/O
Jls
Adj.
Run.
Date
From
To
Total
H/O
Jls
Adj.
1
1907
2,021,001
2,021,500
500
H
11
Unadj.
43
1915
2,856,401
2,856,700
300
O
11
Unadj.
2
1911
2,337,031
2,337,080
50
O
11
Unadj.
44
1915
2,864,501
2,864,900
400
O
11
Unadj.
3
1912
2,406,001
2,406,050
50
H
11
Unadj.
45
1915
2,867,701
2,868,000
300
H
11
Unadj.
4
1912
2,488,071
2,488,100
30
O
11
Unadj.
46
1915
2,870,001
2,870,200
200
H
11
Unadj.
5
1913
2,488,701
2,488,780
80
O
11
Unadj.
47
1915
2,870,901
2,871,000
100
O
11
Unadj.
6
1913
2,515,401
2,516,000
600
O
11
Unadj.
48
1916
2,876,001
2,876,600
600
O
11
Unadj.
7
1913
2,521,601
2,522,000
400
H
11
Unadj.
49
1916
2,878,101
2,878,650
550
H
11
Unadj.
8
1913
2,551,201
2,551,700
500
O
11
Unadj.
50
1916
2,878,701
2,879,000
300
O
11
Unadj.
9
1913
2,558,001
2,558,100
100
H
11
Unadj.
51
1916
2,886,001
2,886,100
100
O
11
Unadj.
10
1913
2,558,601
2,559,000
400
O
11
Unadj.
52
1916
2,886,901
2,887,000
100
O
11
Unadj.
11
1913
2,573,401
2,573,700
300
H
11
Unadj.
53
1916
2,893,001
2,893,300
300
O
11
Unadj.
12
1913
2,585,801
2,586,000
200
O
11
Unadj.
54
1916
2,904,701
2,905,000
300
H
11
Unadj.
13
1913
2,589,001
2,589,300
300
O
11
Unadj.
55
1916
2,908,001
2,908,100
100
H
11
Unadj.
14
1913
2,594,201
2,594,500
300
H
11
Unadj.
56
1916
2,908,901
2,909,000
100
O
11
Unadj.
15
1914
2,596,401
2,597,000
600
O
11
Unadj.
57
1916
2,911,001
2,911,500
500
O
11
Unadj.
16
1914
2,609,801
2,610,000
200
O
11
Unadj.
58
1916
2,914,101
2,914,500
400
O
11
Unadj.
17
1914
2,626,001
2,626,300
300
O
11
Unadj.
59
1916
2,919,001
2,919,600
600
O
11
Unadj.
18
1914
2,626,801
2,627,000
200
H
11
Unadj.
60
1916
2,924,501
2,925,000
500
O
11
Unadj.
19
1914
2,632,001
2,632,200
200
H
11
Unadj.
61
1916
2,927,001
2,928,000
1,000
O
11
Unadj.
20
1914
2,632,801
2,633,000
200
O
11
Unadj.
62
1916
2,931,001
2,931,200
200
O
11
Unadj.
21
1914
2,641,001
2,641,300
300
O
11
Unadj.
63
1916
2,931,901
2,932,000
100
O
11
Unadj.
22
1914
2,657,601
2,658,000
400
O
11
Unadj.
64
1916
2,933,001
2,933,300
300
O
11
Unadj.
23
1914
2,659,001
2,659,300
300
O
11
Unadj.
65
1916
2,944,301
2,944,400
100
O
11
Unadj.
24
1914
2,659,801
2,659,900
100
H
11
Unadj.
66
1916
2,948,501
2,948,800
300
O
11
Unadj.
25
1914
2,664,001
2,664,100
100
H
11
Unadj.
67
1916
2,958,001
2,959,000
1,000
O
11
Unadj.
26
1914
2,671,201
2,671,600
400
H
11
Unadj.
68
1916
2,991,601
2,991,700
100
H
11
Unadj.
27
1914
2,687,401
2,687,700
300
O
11
Unadj.
69
1916
2,997,001
2,998,000
1,000
O
11
Unadj.
28
1915
2,690,601
2,690,700
100
O
11
Unadj.
70
1916
3,021,001
3,022,000
1,000
H
11
Unadj.
29
1915
2,733,201
2,733,400
200
O
11
Unadj.
71
1917
3,066,001
3,067,000
1,000
O
11
Unadj.
30
1915
2,743,600
2,743,900
300
O
11
Unadj.
72
1917
3,075,001
3,076,000
1,000
O
11
Unadj.
31
1915
2,748,801
2,749,000
200
H
11
Unadj.
73
1917
3,132,001
3,133,000
1,000
O
11
Unadj.
32
1915
2,753,001
2,753,200
200
O
11
Unadj.
74
1917
3,139,251
3,139,300
50
H
11
Unadj.
33
1915
2,763,901
2,764,000
100
O
11
Unadj.
75
1917
3,169,001
3,169,220
220
O
11
Unadj.
34
1915
2,775,001
2,775,100
100
O
11
Unadj.
76
1917
3,169,401
3,170,000
600
O
11
Unadj.
35
1915
2,776,101
2,776,400
300
O
11
Unadj.
77
1917
3,180,601
3,181,000
400
O
11
Unadj.
36
1915
2,783,301
2,783,800
500
H
11
Unadj.
78
1917
3,203,001
3,203,200
200
H
11
Unadj.
37
1915
2,804,901
2,805,000
100
O
11
Unadj.
79
1917
3,203,201
3,203,700
500
H
11
Unadj.
38
1915
2,819,001
2,819,200
200
O
11
Unadj.
80
1917
3,203,701
3,204,000
300
H
11
Unadj.
39
1915
2,837,521
2,837,570
50
O
11
Unadj.
81
1917
3,240,001
3,240,900
900
O
11
Unadj.
40
1915
2,837,601
2,837,900
300
O
11
Unadj.
82
1918
3,292,001
3,292,600
600
O
11
Unadj.
41
1915
2,842,801
2,843,000
200
O
11
Unadj.
83
1918
3,305,801
3,305,900
100
O
11
Unadj.
42
1915
2,849,001
2,849,400
400
H
11
Unadj.
84
1918
3,305,901
3,306,000
100
O
11
Unadj.
    Total
28,480
 
Name
H/O
Estimate
Name
H/O
Estimate
Andrews Bros Olean Ny.
11 Jewels O.F.
100
Illinois Watch Co.
11 Jewels H.
4,930
Ariston Jr, U.S.A. [Made for Marshall Field]
11 Jewels O.F.
50
G J Kasper Cleveland Ohio.
11 Jewels H.
50
L S Caldwell, Wildwood NJ.
11 Jewels O.F.
200
Mueller's " Little Anthony " Baltimore
11 Jewels O.F.
20
Chronos
11 Jewels O.F.
200
B Olbricht, Brooklyn Ny.
11 Jewels O.F.
200
Chronos
11 Jewels H.
100
Precise
11 Jewels O.F.
100
P A Goodnough, Erie Pa. 'Specially Made For'
11 Jewels O.F.
100
Railroad Dispatcher [Made for J M Roberts Pittsburgh Pa.]
11 Jewels O.F.
200
Hennegen - Bates Co. Baltimore MD.
11 Jewels O.F.
200
Railroad Dispatcher [Made for J M Roberts Pittsburgh Pa.]
11 Jewels H.
50
Hess & Culbertson Jewelry Co. St Louis.
11 Jewels H.
20
Charles F Sarbaugh, Hanover Pa.
11 Jewels O.F.
50
Illinois
11 Jewels O.F.
4,250
Simons Jewelry Co. Ia.
11 Jewels H.
30
Illinois
11 Jewels H.
1,900
Sorensen Co. S.F. Cal. 'Special'
11 Jewels H.
20
Illinois Watch Co,
11 Jewels O.F.
14,520
Jason Weiler  & Sons Boston
11 Jewels O.F.
380
Grade 401 Movements found to date.
Grade 401 Runs.
Serial numbers used on this page by the kind permission of  
Russell W Snyder
Last update 01/11/2016.
Grade 401,
11 jewels unadjusted, manufactured from 1907 to 1918 a total of 28,480 movements in 84 runs make up this grade. Model 3 open faced and model 4
hunter; bridge movements of lower quality,  with single roller and patent micrometric regulator. Open faced 21,130 in 59 runs and Hunter 7,350 in 25
runs.

Observations,
The movements are mostly radial etched pattern demaskeening with the majority named Illinois and Illinois Watch Co., named and private labels make
up the remainder. The first run of grade 401; 500 hunter movements were made in 1907, although it was 1911 that the bridge models come into full
production in other grades.

Variants,
Two types of escapement bridge can be found, the majority have the two fingered bridge. The Ariston movements have a full plate bridge.

Description,
11 jewels, composition settings, compensating balance with timing screws, exposed escapement, patent safety center pinion;, best quality Swiss
Breguet hairspring, patent micrometric screw regulator; Swiss mainspring; sunk second dial set in recess of plate; exposed winding wheels; recoil click;
friction fitted dust band, attractively demaskeened.
Images of models in this grade showng types of escapement bridges.