The letter is from Adam Hilger Ltd to John Evershed, Director of Solar Physics Observatory Kodaikanal. It replies that the three 60° flint prisms are in stock but unfinished. Also, the two-plane parallel glass and the pair of green glass will be sent together to absorb the violet and ultra-violet rays. It also discusses the lack of immediate possibility for finishing the 6" diameter object glass.
Evershed, JohnElements area
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