Wisconsin State Agricultural Society. 
113 
should be solid, or would iron rolled up without being welded and 
connected at the edges be sufficient? 
Professor Sterling. You know how the scroll rod is construct¬ 
ed. They are scrolls which are inserted into each other. I do not 
see any objection to that. If you have parts of iron, they ought to 
be intimately connected on the surface; and they are generally 
made to screw into each other. In regard to the practical way of 
effecting this, I don't know that I can give any opinion. 
The rod which was manufactured at Janesville some time ago, a 
continuous copper rod without any break in it at all, in my 
judgment was one of the best rods we ever had. I believe the man¬ 
ufacturing of that rod has ceased. The edges were folded in, and 
it was entirely continuous, without any breaks in it at all, and in 
each of those p^rts where it was rolled you could put in wire to 
stiffen it if you wished. This scroll rod I think is very good if it is 
properly put up. 
Mr. Benton. Is not the common inch gas-pipe made of galvan¬ 
ized iron with the ends screwed together firmly, a good conductor? 
Professor Sterling. I meant to have tried an experiment in re¬ 
gard to galvanized iron, as to its conductive quality, but I did not 
have time. It is stated in Chamber’s Encyclopedia that it is a bet¬ 
ter conducting metal than iron, but iron in the form of those gas- 
pipes is just as good as though it were solid, as you have less mate¬ 
rial and more surface. 
OBJECTS AND METHODS OF CULTIVATION. 
✓ 
BY PROF. W. W. DANIELLS, UNIVERSITY OF WISCONSIN, MADISON. 
In all the operations intended to aid his crops in obtaining food 
for a vigorous and productive growth, the farmer needs to regard 
the soil as the only source from which that food can be obtained. 
Plants do, indeed, draw a large portion of their subsistence from 
the air. But the supply from that source is always abundant, and 
to effect it in any way either in quantity or quality is impossible 
for man. 
The soil is the great store-house of the mineral constituents of 
plant food, and it is to the increase of these constituents, either di¬ 
rectly or indirectly, that the farmer must turn his attention. 
To obtain this increase, he plows, harrows, cultivates, drains and 
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