--------+---------+--------------+------------+---------+------------ I. | II. | III. | IV. | V. | VI. --------+---------+--------------+------------+---------+------------ Scale | Wave- | E. | L. |(E × L) /| Persistency number. | length. | Reduction of | | 160 | curve | | original | Luminosity | | 650 / E | | luminosity | of | | (Maximum= | | in millionths| original | | 100). | | to cause | beam. | | | | extinction. | | | --------+---------+--------------+------------+---------+------------ 38 | 5172 | 6·9 | 41·5 | 2·86 | 94·2 37 | 5128 | 7·1 | 37·5 | 2·66 | 91·6 36 | 5085 | 7·4 | 33·5 | 2·48 | 87·8 35 | 5043 | 7·7 | 30·0 | 2·31 | 84·4 34 | 5002 | 8·0 | 26·5 | 2·12 | 81·2 33 | 4963 | 8·4 | 24·0 | 2·02 | 77·5 32 | 4924 | 8·8 | 21·0 | 1·85 | 73·8 31 | 4885 | 9·4 | 18·5 | 1·74 | 69·2 30 | 4848 | 10·0 | 16·5 | 1·65 | 65·0 29 | 4812 | 10·7 | 14·5 | 1·55 | 60·6 28 | 4776 | 11·5 | 13·0 | 1·49 | 56·5 27 | 4742 | 13·0 | 11·5 | 1·49 | 50·0 26 | 4707 | 14·5 | 10·5 | 1·52 | 44·8 24 | 4639 | 18·5 | 8·2 | 1·52 | 34·1 22 | 4578 | 23·0 | 6·3 | 1·45 | 28·3 20 | 4517 | 30·0 | 5·0 | 1·50 | 21·7 18 | 4459 | 39·0 | 4·0 | 1·56 | 16·7 16 | 4404 | 51 | 3·1 | 1·59 | 12·3 14 | 4349 | 66 | 2·3 | 1·52 | 9·85 12 | 4296 | 80 | 1·9 | 1·52 | 8·12 10 | 4245 | 110 | 1·4 | 1·54 | 5·91 8 | 4197 | 154 | 1·0 | 1·54 | 4·22 6 | 4151 | 204 | ·75 | 1·54 | 3·18 4 | 4106 | 307 | ·5 | 1·54 | 2·11 2 | 4063 | 513 | ·3 | 1·54 | 1·26 0 | 4020 | 770 | ·2 | 1·54 | ·84 --------+---------+--------------+------------+---------+------------ From 38 to 64 the extinction is the same as with the central part of the eye. TABLE VIII.--P.’S CURVES[B] (see Fig. 31).