J 835.] Scientific Intelligence. 471 



incorporation of the company has been read a first time in the House 

 of Commons. But before it proceeds further, injustice to all parties, 

 it will be absolutely necessary that more information should be 

 collected. 



IV. — Address to Meteorologists. 



At the suggestion of Sir John F. Hersehel, (Athenaum, April) 

 the Scientific Society at the Cape of Good Hope has agreed to 

 undertake to make horary observations of the barometer, thermo- 

 meter, wet and dry thermometers, clouds, winds, meteors, &c, &c, 

 on four fixed days in each year: viz. 21st of March, 21st of June, 

 21st of September, and 2 1st December, (unless any of these days 

 should fall on a Sunday, in which case, for the 21st substitute the 

 22nd,) at the commencement of each hour, (per clock) mean time at 

 the place for 36 hours, beginning at 6 o'clock in the morning of the 

 21st, and ending at 6 o'clock in the evening of the 22nd. Sir John 

 Herschel himself adds, " If possible, get meteorologists in England, 

 and elsewhere, by land and by sea, over the whole globe, to set 

 apart these four days as great meteorological festivals, when every 

 man is to be at his post." 



It is only necessary to add that a portion of the " Records" will be 

 preserved for the insertion of a summary of such correct registers as 

 may be kept in this country, on these days ; we hope that meteorolo- 

 gists will be up and stirring. 



V. — Postscript to Mr. Walkers Paper on the 

 Adjustment of the Eye, 6fc* 

 Sir, Manches terMay Wth, 1835. 



May I request that you will do me the favour to insert, in 

 your next Number, the following postscript to my paper " On the 

 Adjustment of the Eye, &c." 



To make my account complete, I ought, perhaps, to have added, 

 that the converse of the proposition is also established by the experi- 

 ments which I have made with the optical instrument described ; for, 

 with a contracted pupil, distant objects are but obscurely represented 

 on the retina, and those only which are well portrayed are such as 

 stand out in strong relief. So that it is quite apparent that whilst 

 on the one hand a contracted state of the pupil renders near objects 

 distinct ; on the other hand, to obtain a correct picture of distant 

 objects, and more particularly a wide range of vision, it is essential 

 that the pupil should be rather dilated. With the instrument adap- 

 ted for the representation of distant objects, if it be desired to produce 

 a perfect picture of a near object by altering the relative position of 

 the lens and the retina, it is necessary to remove the latter to a 

 distance of not less than two inches from the former, That a corre- 

 sponding change of this description can take place in the human 

 eye will hardly be supposed. 



I am, Sir, 



Your very obedient Servant, 



John Walker . 

 To the Editor of the u Records of General Science." 

 * See vol. i. p. 368. 



