462 



NOTES AND QUERIES. 



[No. 184. 



J. C. B. will find this subject fully treated in 

 Didron's Christian Iconography, Bohn's edition, 

 pp. 405. 412. ; and an illustration of the Latin 

 benediction at p. 205., and the Greek benediction 

 at p. 176. Ceykep. 



PHOTOGRAPHIC NOTES AND QUERIES. 



New Developing Fluid. — Dr. Diamond has re- 

 ported very favourably of the developing fluid, 

 which I spoke of in " N. & Q." of March 12 as 

 "being simple, inexpensive, and keeping good a 

 length of time." In accordance with what I then 

 stated, I herewith give the readers of " N. & Q." 

 the benefit of it, and leave them to form their own 

 opinion of its value after trying it : 



Protosulphate of iron - 12 grs. 



Nitrate of lead - - 8 grs. 



Water - - - - 10 drs. 



Acetic acid - - - i dr. 



Dissolve the protosulphate of iron in the water ; 

 then throw in the nitrate of lead in powder ; stir 

 with glass rod until it is dissolved ; keep stirring 

 while pouring in the acetic acid, and for a few 

 minutes afterwards. Let the precipitate subside, 

 then filter. I have used nothing else for positives 

 on glass since I discovered the preparation. I 

 have not tried it for developing in the wax-paper 

 or other paper process. The liquid is colourless 

 as water when first made. By long keeping it 

 will change colour, but throws down no deposit, 

 nor loses its properties. If those gentlemen who 

 try it would give their opinions of it, I should be 

 obliged. J. L. Sisson. 



Edingthorpe Rectory. 



[Since this was in type, Mr. Sisson has written to 

 say, that he has been informed that the use of nitrate 

 of lead has already been recommended by Mr. W. 

 Brown. Mr. Sisson was not aware of that fact, but 

 is unwilling to appear in any way to appropriate to 

 himself the suggestion of another. — Ed.] 



Photographic Tent. — Can any of your readers 

 inform me how, or where, to procure an effective 

 tent for photographic operations out of doors ? All 

 those I have yet seen are sadly wanting in the 

 two great essentials — portability and cheapness. 

 If any one could suggest the means for supplying 

 the desiderata, it would prove in the coming 

 season a boon to photographers at large, and con- 

 fer a favour on M. F. M. 



Mr. Wilkinson's simple mode of levelling Cameras. 

 — The following ingenious suggestion appears in 

 the 3rd Number of the Journal oj" the Photographic 

 Society, and deserves to be widely circulated. " My 

 plan is to place a T-square on the bottom of the 

 camera, and draw one perpendicular line on each 

 side (exactly opposite to each other), either with 

 paint or pencil ; or the ends of the camera itself 



will do if perpendicular to the base. Then, having 

 two musket bullets attached to a silk thread, 

 simply hang them over the camera, and everything 

 required will be attained much quicker by these 

 plumb-lines, and with accuracy equal to the spirit-» 

 levels. The advantage of the simple contrivance 

 of two bullets suspended by threads is, that when 

 the thread is laid across the camera, it is at once 

 seen whether the thread touches all tlie way down 

 both sides ; if not, one or other side of the camera 

 is raised, until the thread lies close on each side : 

 this gives the level crossways. The other perpen- 

 dicular of the line is then sought for, and the back 

 or front of the camera raised or lowei-ed, until the 

 thread cuts the line drawn below. Here then we 

 have the most perfect line that can be obtained, at 

 the expense of two bullets and a bit of silk, 

 answering every purpose of the best spirit-level, 

 and applied in one-half the time. It has since 

 occurred to me, that as we sometimes require to 

 measure the distance for stereoscopic pictures, this 

 thread ought to be about three feet long ; and wo 

 might as well make three knots, and then we 

 should have the measure of a three-feet rule 

 always with us. It has also occurred to me, that 

 in taking portraits you sometimes require to have 

 a measure of time ; and by a little modification we 

 have here the most accurate chronometer that can 

 be produced. Instead of three feet, I make it 

 thirty-nine inches and the decimal necessary, say 

 two-tenths from the centre of support to the centre 

 of the bullet. I then get a pendulum which vibrates 

 to second exactly, from the point of suspension to 

 the point of oscillation. I hang it by a pin, and I 

 there have a chronometer of the greatest possible 

 accuracy ; and I can employ it for taking portraits 

 of one, two, three, or four seconds : it will vibrate 

 for a minute. Consequently I have a mode of 

 levelling my camera with the greatest accuracy, a 

 measure of time, and a measure of distance ; and 

 all at a cost considerably under one penny." 



Antiquarian Photographic Club. — This asso- 

 ciation for the interchange of photographic views 

 of objects of antiquarian interest, has now nearly 

 attained the number of members to which it is 

 proposed to limit it. For the few remaining va- 

 cancies preference will be given, for obvious 

 reasons, to parties resident in varied localities. 

 Any gentlemen or ladies desirous to join the club, 

 may send their names, with specimens of their 

 skill, to the Honorary Secretary, care of Mr. Bell, 

 186. Fleet Street. The amount of the annual 

 subscription is not yet fixed, but as all that can be 

 required will be to meet the expenses incident to 

 the receipt and interchange of the photographs, it 

 must necessarily be very limited. 



