268 



THE YEAR-BOOK OF AGRICULTURE. 



squared ; but although the sap of live oak and white oak is less durable than the heart, it ia 

 generally received with the heart and as merchantable timber. 



The lasting property of live oak consists chiefly in its being devoid of that acid juice which 

 white oak contains. But this is not all : the whole of the capillary tubes seem to be com- 

 pletely coated and filled with a greasy, glutinous substatfce that is not found in the sap, 

 which is doubtless the reason why the sap is not rendered equally durable. This substance 

 may be brought out for analyzation by steaming: it takes steam quite as well,df not better, 

 than yellow pine. The monthly tables of specific gravity of the green tree furnishing us, as 

 they do, a basis of (doubtless) the most reliable series of experiments ever undertaken in 

 this or any other country, will, we think, be examined with interest by mechanics, and par- 

 ticularly those whose business it is to use the three kinds of timber of which they take cog- 

 nizance. In addition to the monthly tables, Mr. Jarvis has furnished us with the mean 

 specific gravity as made up of twelve months, and carried the whole out into pounds and 

 ounces avoirdupois. 



GREEN TREE. 



Specific Gravity of Timber fresh from the Forest, none of which was felled more than ten days 

 before the Specific Gravity was obtained. 



ROUND LIVE OAK. 



Month felled. Specific gravity. 



September 15 1-144 = 71 10 



October 15 1-173 = 73 5 



November 15 1-182 = 73 14 



December 15 1-186 = 74 2 



January 15 1-194 = 74 10 



February 15 1-173 = 73 5 



March 15 1-187 = 74 5 



Aprillo 1-193 = 74 9 



May 15 1-182 = 73 14 



June 15 1-154 = 72 2 



July 15 1-148 = 71 12 



August 12 1-176 = 73 8 



SQUARE LIVE OAK. 



Month felled. Specific gravity. 



Ibs. oz. 



September 15 1-242 = 77 10 



October 15 1.273 = 79 9 



November 15 1-274 = 79 10 



December 15 1-283 = 80 3 



January 15 1-283 = 80 3 



February 15 1-252 = 78 4 



March 15 1-261 = 78 13 



April 15 1-244 = 77 12 



May 15 1-258 = 78 10 



June 15 1-257 = 78 9 



July 15 1-239 = 76 15 



August 12 1-245 = 77 13 



ROUND WHITE OAK. 



Month felled. Specific gravity, 



ibs. oz. 



September 15 -950 = 59 6 



October 15 -997 = 62 5 



November 15 -996 = 62 4 



December 15 1-018 = 63 10 



January 15 1-015 = 63 7 



February 15 1-014 = 63 6 



March 15 1-070 = 67 7 



Aprill5 1-013 = 63 5 



May 15 1-021 = 63 13 



June 15 1-005=62 13 



July 15 1-089 = 68 1 



August 15 1-054 = 65 14 



SQUARE WHITE OAK. 



Month felled. Specific gravity. 



Ibs. oz. 



September 15 1-037 = 64 13 



October 15 1-069 = 66 13 



November 15 1-058 = 66 2 



December 15 1-083 = 67 11 



January 15 1-068 = 66 12 



February 15 1-066 = 66 10 



March 15 1-044 = 65 4 



April 15 1-071 = 66 15 



May 15 1-102 = 68 14 



June 15 1-032 = 64 8 



July 15 1-123 = 70 3 



August 15 1-082 = 67 10 



MEAN SPECIFIC GRAVITY FOR ONE YEAH, 



ROUND YELLOW PINE. 



Month felled. Specific gravity. 



Ibi. oz. 



September 15 -828 = 5112 



October 15 -764 = 4712 



November 15 -777 ='48 9 



December 15 -765 = 47 13 



January 15 -823 = 51 7 



February 15 -789 = 49 5 



March 15 -782 = 48 14 



April 15 -795 = 49 11 



May 15 -744 = 46 8 



June 15 -792 = 49 8 



July 15 -751 = 46 15 



August 15 -772 = 48 4 



SQUARE YELLOW PINE. 



Month felled. Specific gravity. 



Ibs. ox. 



September 15 -665 = 41 9 



October 15 -662 = 41 6 



November 15 -653 = 40 13 



December 15 -639 = 3915 



January 15 -625 = 39 1 



February 15 -673 = 42 1 



March 15 '581 = 36 5 



April 15 -683 = 4211 



May 15 '583 = 36 7 



June 15 -595 = 37 3 



July 15 -655 = 40 15 



August 15 -639 = 3915 



Square pieces of live oak (fractions off) 1-259 = 78 11 



Round 

 Square 

 Round 

 Square 

 Round 



in bark 2-191 = 74 7 



white oak 1-069 = 66 13 



" in bark 1-020 = 63 12 



yellow pine -637 = 39 13 



" " in bark... '781 = 48 13 



Too Many Shade-trees Injurious. 



HON. MR. DICKINSON, an extensive farmer of Steuben county, New York, has recently ad- 

 vanced the idea (says the Rural New Yorker) that no farmer can afford to keep shade-trees 

 elsewhere than by the wayside, and hardly there. Mr. D. carries on a number of faring, 

 upon which, by great expense and labor, he has saved a large number of the finest shade-trees ; 

 but he is now cutting them down, for he farms for profit, and cannot let them stand. The 

 injury they do to a crop in taking up the moisture for some distance around, and leaving the 



