418 Proceedings of the Society of Arts » 



1. Charles Cameron, Esq. Mount Vernon, Libberton. 



2. John Watson, Esq. (of Edinburgh Life Assurance) 11 Salisbury 

 Street. 



3. Charles W. Anderson, Esq. merchant, 13 Annandalc Street. 



4. Alexander Low, Esq. accountant, 11 Albyn Place. 



%th March 1841.— Andrew Fyfe, M.D., F.R.S.E., President, 

 in the chair. The following communications were made : — 



1. Notice regarding a cheap and easily used Camera Lucida, applicable 

 to the delineation of Flowers and other small objects. By Sir John Ro- 

 bison, K.H., F.R.S.E., M.S.A. 



The instrument was exhibited. (783.) 



A piece of Plate Glass is made to stand in a vertical position by means 

 of a support. It rests on a table covered Avith white paper, and the ob- 

 ject is placed on the paper on one side of the glass. On looking down 

 from that side of the glass diagonally, an image of the object is seen on the 

 paper on the other side, and a drawing of it can be readily taken. 



Thanks voted, and Sir John was requested to give a short account of the 

 instrument in writing, to be jjrinted. 



2. On the Building Materials of the United States of North America. 

 By David Stevenson, Esq., civil-engineer, Edinburgh, M.S.A. 



Specimens of the Wood and Marble of that country were exhibited and 

 presented to the Society. (787.) 



Thanks voted, and an abstract to be printed in the Transactions. 



3. Notice and Analysis of the Nodus Rosi, a Phenomenon produced by 

 some pieces of Calcareous Spar brought from Iceland by Mr Rose, and 

 first observed by Mr Nicol. By Edward Sang, Esq. actuary, Edinburgh, 

 M.S.A. 



Specimens producing this beautiful appearance were exhibited. (784.) 

 Thanks voted, and an abstract to be printed in the Transactions. 



4. Description, with a Drawing, of the method of Burning Lime in 

 Persia. By James Robertson, Esq. civil and mining engineer, 4 York 

 Place, Edinburgh. (76G.) Thanks voted. 



5. The Secretary, at the request of Mr Ritchie, Ironmonger, High Street, 

 exhibited Bickford, Smith, and Davey's Patent Safety Fuse, for Blasting 

 Rocks and other Mining Operations. It burns, when tamped, at the rate 

 of a foot and a l^alf per minute, and gives fire with great certainty. It is 

 sold at a moderate price, and in various lengths from 24 feet upwards, and 

 saves much powder in blasting. There is a kind of it made for blasting 

 under water, or in wet ground. Mr D. Stevenson, civil engineer, stated 

 that he had used it successfully in blasting rock five feet under water. 

 (792.) 



6. Donation — Printed account of the nature and properties of Ronnie's 

 Patent Trapezium Paddle- Wheels ; Avith a plate. Presented by George 

 Rennie, Esq. civil eugineer, Whitehall Place, Westminster. (785.) 

 Thanks voted. 



