of the exposure must vary according to the strength of the acid
[&?] copper requires stronger acid & a longer exposure than steel.
My plates were exposed about 1 3/4 minutes. The best way is
to test it on a spoiled plate each time. By pouring off the
acid & stopping out the lights – very beautiful effects can
be produced but I have not attempted this yet.
The priciple precautions are to spread the ground evenly
and securely – it must be neither too hot nor to cold.
I had a good many failures in spreading grounds;
care must also be taken not to scratch the ground – or
there will be some engraving on the plate not desired,
and the acid should be watched carefully & not left
[on?] too long. The burnisher, scraper & graver are useful in
making alterations after the plate is etched. New grounds
can be spread and additions made as often as necessary.
Should you come to Davenport I can show you all the
above much better than I can describe it - and in less time.
It is the most satisfactory mode of illustration I know of.
The whole outfit costs less than $5. The plates (8") cost about
$15 per 1000 for paper & painting. I obtained the materials from
the Franklin Bank Note Co., 107 Liberty St. new York.
It was a great pleasure to me to meet you & [Mr. Aslous?]
in Des Moines – and – hope I may have the pleasure of
meeting you more frequently hereafter.
Our subject that I would have liked to have [?]
to you was about – is the matter of State Entomologist – The
bill introduced by [?] is a copy of the Illinois laws
of 1867 under which Mr. Walsh was appointed, but naming
the Agr. Coll. as depository of the collections, I feel much interest
in having this or some other bill as good or better go into effect.
I lear from Mr. Riley that he would accept the position
if it is offered to him -& the salary is reasonalbe – not less
than $2000. I don't suppose there is any one in the U. S. better
qualified for the position & I hope iowa will have the wisdom
to make this appropriation (instead of the $50000 for grasshopper seed).
Mr. Fosters bill was reported [sic.] back to the senate by the
Agr. Comm. adversely - & has now been referred to the Agr. College
Comm. where I hope it will undergo such changes, as will
make it acceptable to the legislature to the Agr. Coll. to Mr. Riley. You
know what is to be done to get it through better than I
do - but if you can do anything more please let me know.
I should like very much to learn your views upon this
matter & will act with you to the best of my ability.
If you wish any further information about the [?]
[?] position or better make us a visit in Davenport.
With best regards
Truly your friend
J. Duncan [Butram?]
