A little ramble through 19th century astronomy - astronomical photogrphy in 1874

 Nature February 26^th 1874 

Astronomische Nachrichten No. 1973 

In this  number Dr Stein gives an account of an apparatus for astronomical photography, with which the negative taken without the use of a dark room or tent, and if useful in practice, it justly deserves credit.

It consists practically of a sort of flat box or glass, one side of which is the collodionised which fits water tight against the other sides by means of India rubber packing. There is a tube passing into this box through which first the ordinary silver solution is poured, and then by laying the collodionised plate downward it is covered by the solution and sensitised; this is then drawn off, and the box which is contained I n a suitable holder placed on the telescope and exposed by drawing away the non actinic glass cover in front. After exposure the covered glass is replaced, the box removed and developed bu pouring in the solution in the same manner as the silver, in the meantime watching the plate through the coloured glass; the washing is then proceeded with in the same manner. Dr Stein proposes to use this method for photographing the Transit of Venus. 

Prof Schmidt contributes a paper on the rotation of Jupiter, in which he discusses all the old observations of Cassini and others. From his list we gain that these observers differed to the amount of 6 minutes, the minimum being 9 hours and 50 minutes and the maximum 9 hours and 56 minutes. From Prof Schmidt’s observations in 1873 he obtains a period of 9 hours 56 minutes and 7.2 seconds.

 

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