BEPORT OF THE ANTUROrOMETRIC COMMITTEE. 



261 



Inspector- General Lawson, who has prepared the Tables XI. to XIV, on 

 Eyesight, has contributed the folloiving remarks upon them. 



The acnteness of vision lias beer* tested by finding the distance at 

 ■which the individual under trial could distinguish the dots on the cards 

 issued by the Committee, so as to count them readily. These cards 

 contain eighteen square dots of one-fifth of an inch wide placed iri'egu- 

 larly in two groups, the distances from centre to centre of the contiguous 

 dots varying from 2 diameters to 316 ; their intervals may accordingly be 

 taken at one diameter less, or from 1 to 2 '16. Of these intervals five are 

 of 1 diameter, six of 1'24, two of 1-83, and three of 216, and, if the 

 acuteness of vision were fairly tested, it must have been equal to sepa- 

 rating the dots with the intervals of one diameter sufficiently, at the 

 distance noted for each individual, to enable him to count them. 



On approaching such a card, from a distance, the dots with the larger 

 interspaces become distinct, while those with the smaller still seem con- 

 tinuous ; but after a few trials many of those under test will become 

 aware that the elongated-looking dots are made up of two, though they 

 be too far ofi" for the eye to separate them. 



The individuals examined have been distributed i]i five classes ac- 

 cording to the scheme detailed in Table 111. of the Committee's Report 

 for 1880 ; the details for each class are given in the Tables XI. to XIV. ^ 

 On looking over these the fluctuations in the distance for consecutive 

 years of age are far too great to admit of any satisfactory conclusions; 

 to obviate this the ages have been grouped in five -yearly periods up to 

 thirty, after which ten-yearly periods have been employed ; these reduce 

 the fluctuations materially and afi"ord much more harmonious results, as 

 will be seen in the following abstract. 



Distance at which the test-dots were distinguished at different ages 

 in each of the five classes, with a general mean for the II. 111. IV. and 

 V. Classes, and a separate one for the IV. and V. Classes. 



' For the reasons stated below, it has not been considered necessary to give the 

 Tables for Class I. in a separate form. 



