PREEPACE. VO, THE: SLeTH- EDITION. 
The growing interest shown in the culture of silk, in the United States, 
is attested by the demands upon this Department for copies of this man- 
ual, which has hitherto been published as Special Report No. 11. Origi- 
nally prepared as a brief manual, based on my own experience of the 
industry in America, the present demands of silk-growers, or rather of 
those desirous of becoming such, call for some further details, and in 
elaborating the work it has been thought best to include it among the 
bulletins of the Division. I have also divided the matter into chapters, 
and those on the implements which are necessary to, or facilitate, the 
work; those on diseases, reproduction, reeling, and the physical prop- 
erties of raw silk embrace essentially new material, parts of Chapters 
V and VI being from my current annual report not yet distributed. 
In Chapter VIII, in speaking of machinery I have omitted the de- 
tailed descriptions of special machines given in former editions and ex- 
plained rather the mechanical principles that should be involved in all. 
A description of the Serrell Keel would have been very appropriate, but 
the inventor has been promised by the Commissioner that such should 
not be made public until all patents are secured. I shall hope to elab- 
orate this chapter in some future edition. 
It must not be forgotten that the original manual was never intended 
as an extended treatise on silk-raising or reeling, but was prepared to 
give,in a simple and most condensed way, information to those inter- 
ested, and in a form applicable to the United States. It is gratifying 
to know that a number of other pamphlets on the Silk-worm have of 
late years been published, and that this manual has been quite freely 
used in their preparation. In one instance, in fact, an almost verbatim 
copy has been published and sold privately. I have found little or no 
occasion to alter opinions expressed in the manual, but in the present 
edition have revised the estimates of profits given in the Introduction 
to the original edition, leaving out those on egg production, because of 
the changed conditions since 1879, which have rendered such work, as 
a profitable business, obsolete in this country, and the production of 
sound and reliable eggs much more difficult and expensive. 
Though particular pains were taken to impress upon readers the fact 
that the estimates of profits in silk-raising were based on definite mar- 
ket prices at that time, and that prices and profits must needs, as in all 
trades, vary from year to year, and though I especially omitted the 
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