249 



(4) Oue tliickucss of inatoliecl boards with paper on the studdiug. Thirteen of 

 these .sik)s iiave been visited, 6 of wliieh, with an average age of 3 years, are iu good 

 couditiou still, Avhilo 7, with an average age of 3.43 years, are rotting more or less. 



(5) Two thiekuesses of boards with paper between, nailed closely and llrmly 

 togetlier. There are 45 of these silos, 26 with an average age of 3 years, in good 

 condition, wiiile 19, Avith an average of 3.4 years, are rotting to some extent. 



The rotting in most of the cases noted is bj' no means general, and the conditions 

 nuder which it has occnrred may be thns stated : (1) Where there has been inadequate 

 general ventilation, 8; (2) where stone walls have been faced with Avood, 8; (3) 

 where boards came against beams or sills, 12 ; (4) Avhere spoiled silage is left piled 

 against the boards, 4; (5) where dirt is piled against or lies behind the lining, 4. 



I believe that the rotting iu every case we have thus far observed iu the walls 

 of Avood silos is attributable to imijerfect ventilation, and that it might have 

 been greatly delayed, if not entirely prevented, by diifereut methods of construc- 

 tion. * * * 



The linings of Avood silos haAC been painted iu various AAays to render them less 

 liable to rot, as follows: (1) Paint of any kiud, (2) Avith hot coal tar, (3) with coal 

 tar dissolved in gasoline, (4) with hot coal tar mixed Avith ]iitch, (5) with pitch 

 aloue, (6) with liuseed oil and red ocher, (7) with linseed oil alone. 



As far as can be deduced from a study of the silos visited, there appears to be A^ery 

 little if any adA^antage deriA'ed from the use of the paints mentioned. 



Paiuting- may even liasteu decay. Some antisei)tic liquid might be 

 used, but tests are required to determine what is a good preparation 

 for this purpose. 



Stone and (jroul silos. — We have examined 14 silos which are stone or grout and 25 

 which are stone or grout below and wood above. The masonry of nearly all of these 

 silos is plastered Avith one or more coats of some variety of Avater lime or cement, 

 and Avhere the work is well done the great majority of the testimony goes to shoAV 

 that the silage iu contact Avith the masonry is just as good or e\'en better than 

 against the Avood. ^ * * While it is true that the acids of the silage decompose 

 the cement of the stone silos, still the life of a single heavy coat, well put on and 

 protected from frost, appears to be at least 10 years, and Avith a yearly whitewash- 

 ing with pure cement, I have no doubt that a single coat of plastering might last 

 20 to 30 years. 



Where the Avails of stone silos have been left rough and uneven through insuffi- 

 cient pointing or not plastering them, the settling of the silage develojjs air spaces 

 against the Avails, which result in more or less silage spoiling ; this fact coupled Avith 

 another, a iz, that the earlier stone silos Avere comparatively shalloAV, has been, iu 

 my judgment, the chief cause of unfavorable criticism of these structures. The only 

 serious objection I can urge against a Avell-bvdlt stone silo is its relatiA'ely high tirst 

 cost. 



Silos lined ivith other materials. — The 10 hithed and phistered silos 

 examined all showed cracks and the disintegrating effects of tlie acids 

 in the silage. Serious objections to this kind of lining are stated. 



At the station are 2 silos lined with metal, 1 with sheet iron and the other 

 with roofing tin. They have each been iu use 1 year, and in my judgment are not 

 likely to proA'e satisfactory. None of the aA'ailable metals are in themselves jiroof 

 against the acids of the silo, and it is difficult to coat them in such a way as to 

 entirely shut off the acids. * * * 



I haA-e seen but 1 paper-lined silo, and it is Aery unsatisfactory. * * * 



The 2 shingled silos were in a fair state of preserA'ation, and the silage is 

 reported to have kept well in them. In these cases cull shingles had been used at 

 60 cents per thousand. 



Such a lining is necessarily less perfect, and I believe not as lasting as plain 

 1033G— iS^o. 4 4 



