April io, 1S95.] 



Garden and Forest. 



H3 



Oaks decays but slowly, and hence does less for the improve- 

 ment of the soil. But the saying that " Red Oak and Black 

 Walnut poison the soil" is probably an overstatement — at 

 least, we have no knowledge tliat this is really so or any 

 reason to believe it ; they are simply less useful in making 

 humus. 



Of much more moment fo tree-life than the minerals, is the 

 water of the soil, and in respect to the amout of water tran- 

 spired, trees dilTer very widely, so that, in general, deciduous- 

 leaved trees may transpire six times as mucli as coniferous 

 trees. The Pmes especially are moderate users of water. 

 These latter are satisfied with such small amounts, that they 

 can occupy the dry sands of the Pine-barrens to the exclusion 

 of other species. 



The deterioration of soil under given trees, then, depends 

 upon the rapid exhaustion of the soil moisture. This exhaus- 

 tion is, however, much less due to the transpiration by the 

 trees themselves, than to the surface evaporation, and this 

 again is dependent upon the amount of shade which the trees 

 exert. Under a dense growth of the shady Beech, Hemlock, 

 Spruce, Sugar Maple, etc., no exhaustion of moisture takes 

 place, while under the light-foliaged Birch or Oak, especially 

 in later life when the crowns become thinned out, the sun 

 reaches the soil readily and much water is evaporated. In ad- 

 dition, if these trees stand alone in a field, the raindrops readily 

 fall through the foliage upon the soil and compact it ; thus 

 much less water can percolate and the evaporation from the 

 compacted soil is increased, as every farmer will understand 

 who cultivates his crop in order to reduce evaporation. 



As far as inlluence upon neighboring crops is concerned, 

 trees exert a deleterious influence upon the immediately ad- 

 joining portions either by their shade — and some species are 

 shadier than others, hence a difference in degree of effect — or 

 by their competition for moisture. Some kinds, like Cotton- 

 woods, Willows and Elms, require not only more water than 

 others, but their root systems are capal)le of rapid and enor- 

 mous extension in search of water, so that their influence is 

 far-reaching. Grape-vines are of the same nature, so that it is 

 almost useless to cultivate in the neighborhood of a vineyard, 

 unless the soil contains a superabundance of moisture. 



The taproot trees are less injurious, because they supply 

 themselves from greater depths, while the shallow-rooted 

 ones, like Black Locust, Beech, Spruce, etc., compete on the 

 same level with the annual crops. 



I 



The Kerosene Attachment for Spra3'ing Pumps. 



N a brief report of a meeting of the Association of Economic 

 Entomologists, in the last volume of Garden and Forest, 

 page 480, iTiention is made of the implement devised by me, 

 by means of which kerosene is mixed with water at the instant 

 it passes through a spraying nozzle, so as to obviate the need 

 of making an emulsion jireviously. The machine was ar- 

 ranged so that the piston drav/s on both the water and the 

 kerosene supply at once and mintrlts tlie two fluids in correct 

 proportions. Mr. Marlatt, of the Department of Agriculture, 

 stated that the practical working of the machine with him had 

 rendered any application of the oil dangerous to plants, since 

 it was impossible to foretell the percentage of each substance 

 used. In my own work with this attachment every trial but 

 one was satisfactory so far as 

 the destruction of the insects was 

 concerned, nor was there any 

 case where the foliage was in- 

 jured except in one instance 

 where fitteen per cent, of kero- 

 sene was purposely used on the 

 Raspberry. Mr. Marlatt's work, 

 however, has led me to make a 

 more careful study of the ap- 

 paratus, and I offer here a report 

 of my experiments : 



I find tliat there are two rea- 

 sons why the apparatus I have 

 used is liable to throw variable 

 quantities of kerosene. The va- 

 rying level of the two liquids is 

 one, and the fact that the air- 

 chambers of the pump is lo- 

 cated directly above the dis- 

 charge-pipe is another. The first is liable to cause inequality 

 by varying the heights to which the two liquids are lifted ; the 

 second by permitting the kerosene to accumulate in the por- 

 tion of the pump-chamber located above the discharge-pipe. 



Fig. 21. — Rcspfvoirs for Waterand 

 Kerosene attached to force-pumps. 



water reservoir, 



Fi^ 22. — Imliroved ;iir-chamber of 

 spray-pump. 



away to show the mouth 

 the bottom of this basin 



and this accumulation is forced down and out whenever the 

 pressure in the chainber is relaxed. Both of these inequalities 

 are, however, capable of easy remedy by changing the form 

 of the reservoir to hold the liquids, and by altering the rela- 

 tive position of the air-chamber and discharge-pipe of the 

 pump. 



~ ' I used a five-gallon tin can, to 



which were attached three legs 

 near the top (as shown in 

 figure 21), on which it can 

 stand securely in an invert- 

 ed position. Then a tin basin 

 was attached to these legs at 

 such a position that when the 

 can is inverted the bottom of 

 the basin hangs an inch and 

 a half beneatii the mouth of 

 the can. In the drawing (see fig. 

 21) the front side of this basin 

 is represented as being cut 

 of the can. In the centre of 

 is soldered a neck to which a 

 screwcap is fitted. Through this neck the tube of a funnel 

 can be passed, so that it will enter the mouth of the can for 

 filling. 



Near the top of this can (or near the bottom when in its 

 inverted position) is soldered a staple of heavy tin, to which is 

 attached, by means of a hook, a one-gallon can, with a basin 

 suspended beneath its mouth, as in the larger can, the smaller 

 can being used for kerosene. The kerosene can is hung at 

 such a point that its mouth is on a level with that of the larger 

 can. This arrangement maintains the two liquids at practi- 

 cally uniform levels. The suction pipes are placed in the 

 basins, and the liquids are supplied from the cans as fast as 

 tliey are drawn out. 



The change made in the pump will readily appear in fig. 22, 

 which is intended to show the air-chamber of the Climax pump. 

 The discharge was originally aiA, and the part of the chamber 

 above this orifice answered as the air-chamber. I attached the 

 discharge at B, and extemporized an air chamber at A by 

 uniting sections and fittings of gas-pipe. With this arrange- 

 ment there is no opportunity for the kerosene to accumulate 

 by separation above the discharge-pipe. Should a very little 

 accumulate in the air-chamber, it is not likely to be forced back 

 until after the pumping has ceased. 



With this arrangement of the pump and the reservoirs I 

 have secured excellent duplicates in the proportions of kero- 

 sene distributed at different times. In these trials a Nixon 

 nozzle, with a fine orifice diaphragm and medium gauze, was 

 used, and a second diaphgram with a fine orifice was added at 

 the union of the hose with the pump, which I find increases 

 the intimacy of the mixture. The stream was permitted to 

 flow for a moment after starting the pump, after which it was 

 directed into graduated glass cylinders of 500 cc. capacity, and 

 three cylinders were filled in each trial, sometimes in imme- 

 diate succession, and sometimes the spray was directed else- 

 where for a time after filling one before it was turned into the 

 next. After the cylinders were filled they were permitted to 

 stand for a few hours for the kerosene to separate from the 

 water. The test v/as repeated on several different days, and 

 with the cock in the kerosene tube set to throw quantities of 

 kerosene varying from two to twenty per cent. For some 

 unexplained reason, the proportion of kerosene would increase 

 a little until a few strokes had been made on the pump, but 

 alter this it remained almost entirely constant, rarely varying 

 more than two or three tenths of one per cent, in the different 

 cylinders in the same trial. 



These results are certainly sufficient to show that the 

 difficulties experienced by Mr. Marlatt were due to defec- 

 tive mechanical arrangement, and not to a defective prin- 

 ciple. 



The cans used in my experiments are not expensive, and if 

 well cared for when not in use should last many years. With 

 a properly constructed pump, and with the exerciseof as much 

 care as is necessary in^he use of the Bordeaux or Paris green 

 mixture, the apparatus used in my former experiments will 

 give satisfactory results, so far as destroying insects without 

 harm to foliage is concerned. Still I shall hereafter employ 

 the cans, since they insure a uniform distribution of the kero- 

 sene. The saving in the cost of the soap over using the 

 kerosene-soap emulsion will soon amount to the cost of the 

 cans, and no one who has tried the mechanical method of 

 combining kerosene and water will dispute the great saving 

 of labor effected by it, as compared with the kerosene 



emulsion. 



E.'cpeiiment Station, Madison, Wis. 



£. S. Goff. 



