Proceedings of the Society of Arts. 425 



From the Trans, of the Royal See. of Edin. From the Author. (649.) 

 Thanks voted. 



8. Donation. — Specimen of Lithographed Photography : which was 

 lithographed, transferred, and printed, within two hours after the Pho- 

 tographic impressions were exhibited to the Society, at the meeting on 

 I7th April 1839. By Mr AVilliam Forrester, Lithographer, 14 George 

 Street, Edinburgh. (643.) Thanks voted. 



9. The following Reports of Committees were read and approved of, 

 viz. : — 



(1.) On Mr Roberts' Method of Re-shipping a Rudder at Sea. Mr 

 R. Hunter, Convener. (618.) 



(2.) On Mr Bulloch's Suggestions of Improvement in Cloth Bind- 

 ing, and Sliding-frame. Mr T. Greig, Convener. (629.) 



(3.) On Mr Gilchrist's Substitute for Door Springs. MrSUght, Con- 

 vener. (631.) 



(4.) OnMr D.T.Hope's Paddle-wheel. Mr Maxton, Convener. (642.) 



(6.) On Mr Alston's Prmting in Relief, with Architectural Embel- 

 lishments for the Blind. Mr Fraser, Convener. (639.) 

 Mr Thomas Menzies, Ship-builder, Leith, was admitted an Ordinary 

 Member. 



29//< May. — Su* John Graham Dalyell, Kt., President, in 

 the Chair. The following communications were laid before 

 the Society : — 



1. Notice of a cheap and simple method of preparing Paper for Photo- 

 graphic Drawing, in which the use of any salt oi silver is dispensed with. 

 By Mungo Ponton, Esq., F. R. S. E., For. Sec. Soc. Arts. (654.) Spe- 

 cimens exhibited. The method described by Mr Ponton is to steep the 

 paper in a saturated solution of bichromate of potass, and then to dry 

 the paper quickly at a brisk fire, excluding daylight. This salt is very 

 much cheaper than the salts of silver, and is sensitive enough for litho- 

 graphic and other practical purposes, giving a fine yellow figure of the 

 object on a dark orange or tawny ground. To fix it^ all that is necessary 

 is to immerse the paper in water, which acts on the part of the paper 

 which had not been exposed to the light, while it has no efiect on the 

 dark ground which had been exposed to the sun's rays. The effect is to 

 deprive the yellow of a great part of its colour, and to turn it to stone or 

 cream colour. Thanks voted, and to be printed in the Transactions. 



Dr Fyfc was also requested to give a written notice of his Photographic 

 Experiments, to be printed in the Transactions. 



2. Sir John Robison described verbally the appearance of M. Daguerre's 

 Photographic Pictures, which he had recently an opportunity of examin- 

 ing with much minuteness when in Paris. (656.) Tlianks voted, and 

 Sir John was requested to give a written notice on this subject, to be 

 printed in the Transactions. 



8. Sir Johu Robison also shewed a specimen of a new mode of Casting 



