Back Numbers and Volumes—In reply to many interrogatories ae to what baok numbers and vo- lmes of the Scientific American can be furnished, we make the following statement —Of VolumeB 1, 2 and 3—none. Of Volume 4, about 20 Nos., price 50 cte. Of Volume 5, all but four numbers, price, in sheets, $1. Of Volume , all; price in sheets, $2; bound, $2,75 Of Vol. 7, all; price in sheets. $2; bound, $2,75 Of Vol. 8, none.