+- The Voynich Ninja (https://www.voynich.ninja)
+-- Forum: Voynich Research (https://www.voynich.ninja/forum-27.html)
+--- Forum: Voynich Talk (https://www.voynich.ninja/forum-6.html)
+--- Thread: Morten St George Theory (/thread-2263.html)
Pages:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
RE: Morten St George Theory - -JKP- - 25-04-2019
(25-04-2019, 06:58 PM)Morten St. George wrote: You are not allowed to view links. Register or Login to view....
JP, please note that the plus sign (+) for addition was invented during the middle of the 16th century and hence this marginalia is unlikely to date to the 15th century as you claim.
The plus sign existed in the 15th century in the senses of "positive quantity", "and", and "add":
• Here is an example from a printed book from the 1480s showing surfeits and deficits from Widmann's Mercantile Arithmetic. The minus sign is longer than the modern version, but the plus sign is the same as the one we use today:
![[Image: 220px-Johannes_Widmann-Mercantile_Arithmetic_1489.jpg]](https://upload.wikimedia.org/wikipedia/commons/thumb/3/3b/Johannes_Widmann-Mercantile_Arithmetic_1489.jpg/220px-Johannes_Widmann-Mercantile_Arithmetic_1489.jpg)
Widmann apparently also taught these symbols to his students (they've been found in one of his students' notebooks).
• The plus sign in the sense of "and" (rather than the traditional ampersand) existed in the 14th century in one of the copies of Oresme's mathematical treatise, Algorismus proportionum, 1360.
• The plus sign in the sense of "add" or "add here" was used in the 15th century to mark sections where the rubricator was supposed to add an embellished initial.
RE: Morten St George Theory - Morten St. George - 25-04-2019
RE: Morten St George Theory - -JKP- - 25-04-2019
RE: Morten St George Theory - Morten St. George - 26-04-2019
RE: Morten St George Theory - -JKP- - 26-04-2019
RE: Morten St George Theory - Morten St. George - 26-04-2019
RE: Morten St George Theory - -JKP- - 26-04-2019
RE: Morten St George Theory - Morten St. George - 26-04-2019
RE: Morten St George Theory - davidjackson - 26-04-2019
RE: Morten St George Theory - -JKP- - 26-04-2019