838 



EECREATIVE SCIENCE. 



London ; the other from Mr. Mudd, of Man- 

 chester. 



The cheapest and best plan for an ama- 

 teur, who does not wish to make photography 

 a study, is to go to some respectable dealer 

 in photographic chemicals, and procure all 

 the materials required, as nearly as possible, 

 ready for use. The time was when every 

 photographer prepared his own chemicals. 

 Gun-cotton, and even sether, were his own 

 manufacture (like the artist of the last cen- 

 tury, who had to make his own colours), but 

 now they are to be procured good and cheap, 

 and the time formerly occupied in their ma- 

 nufacture can be much better employed. 



The chemicals required are — 

 Nitrate of silver solution prepared 



for negatives . . . 40 oz. 

 Nitrate of silver fused . . 1 oz. 

 Ponting's or Thomas's collodion 



(negative) 

 Protosulphate of iron crystals 

 Pyrogallic acid 

 Glacial acetic acid . 

 Alcohol .... 

 Bottle of French varnish. 

 iEther .... 

 Hyposulphite of soda (in jar) 

 The apparatus reqiiired are — 



Glass bath and dipper for plates, 11 X 9. 

 Globe plate-holder. 

 Collodion bottle of 4 oz. 



8oz. 

 4 oz. 

 1 oz. 

 4 oz. 

 4 oz. 



4 oz. 

 lib. 



Two porcelain developing cups. 



One, two, and ten-ounce glass measures. 



Two earthenware or porcelain dishes, 



12 X 10 inches- 

 Scales and weights. 

 Glass plates and plate-boxes of the sizes 



required. 



Globe Plate-holder. 



India-rubber finger-stalls for thumb and 

 finger. 



Clean the glasses with a little Tripoli 

 powder and spirits of wine ; wash them well, 

 and polish with a soft cloth, and stow away 

 in the plate-boxes till re- 

 quired. They should be 

 repolished on the day 

 they are to be used. 

 Having procured the ne- 

 cessary materials and ap- 

 paratus, fix the camera on 

 its stand opposite the ob- 

 ject to be copied, in a 

 good light, and move it as near as may be 

 found requisite to take a picture of the size 

 wanted and focus accurately, so as to get an 

 image on the ground glass perfectly sharp ; 

 apiece of black velvet makes „ — ,^,^ 



a good focussing cloth. In 

 copying a map or picture, 

 it is very important that the 

 plane of the camera should 

 be exactly parallel to it, 

 otherwise the image is dis- 

 torted. This is not an easy 

 matter to accomplish by the 

 eye alone ; a long T square, 

 with the top set against the 

 face of the picture, will show 

 at once whether the sides of 

 the camera are at right 

 angles to it or not. 



All being ready in the operating-room, 

 the plate must be taken up by the plate- 

 holder, and its surface dusted with a large 

 camel's-hair brush, and collodion poured on 

 its centre, run round gently to each of the 

 corners, and poured off again into the collar 

 surrounding the mouth of the collodion 

 bottle, from which it will flow into the 

 bottle again; the plate is to be held with 

 the corner downwards, from which the col- 

 lodion has been poured, and a slight rock- 

 ing motion given to it, to prevent the for- 

 mation of lines in the film. When it has set, 



Collodion Bottle. 



