THE GARDENERS' CHRONICLE OF AMERICA. 



readily tlian throii.L;li the voids in the >and. Dust may 

 be left in the crushed stone without fear of its interfering 

 with the strength of the cement, but care should be taken 

 to see that such dust is distributed evenly through the 

 whole mass, and when dust is found in stone, slightly 

 less sand should be used than cirdinarih-. 



As to the size of stone or gravel, this must be de- 

 termined by the form of construction contemplated. The 

 best results are detained by the use of a mixture of sizes 

 graded from small to large. By this means the space or 

 voids between the stones or pebbles are reiluced and a 

 more compact concrete is obtained. Moreover, this 

 method makes it ])ossible to get along w ith less sand and 

 less cement. 



Water for concrete should be clean and free from 

 strong acids and alkalies. If you are at all in doubt about 

 the purity of the water that \ou contemplate using, it 

 would be well to make up a block of concrete as a test, 

 and see whether the cement "sets" properly. 



As above explained, concrete is composed of a certain 

 amount of cement, a larger amount of sand, and a still 

 larger amount of stone (or gravel). To determine how- 

 much of each of these materials to use, we must first con- 

 sider the type of work we wish to undertake. 



There are three kinds of mixtures, in general, in con- 

 crete work : 



1. \'ery wet mi.xture. — Concrete wet en(.iugh to be 

 mushy and run oiT the shovel when handling ; used for 

 thin walls or for thin sections, etc. 



2. Medium mixture. — Concrete just wet enough to 

 make it jelly-like; used for foimdations, floors, etc. To 

 better describe this mixture it may be said that a man 

 should sink ankle deep if he were to step on top of the 

 pile. 



,1. Dry mixture. — Concrete like dani|) earth, used for 

 foundations, etc., where it is important to have the con- 

 crete "set up" as quickly as possible. 



The difiference between the mixtures is, that the dryer 

 the mixture the quicker will the concrete "set up" — but 

 in the long run. wdien carefully mixed and "])laced," the 

 results from any of the above mixtures will be identical. 

 It may be said, however, that a dry mixture is the harder 

 to handle, must be protected with greater care from the 

 sun or from drying too quickly ; and lastly, is likely — 

 unless used by most experienced hands — to show voids or 

 stone pockets in the face of the work when the "forms" 

 are removed. The less the voids in the stone or gravel, 

 the greater will be the volume of the concrete. 



No time should elapse between the "mixing" and the 

 "placing." Directions for placing must of necessity be 

 general, the important thing to remember is, that the 

 materials should not separate in placing. 



In order to obtain a smooth face on the concrete, the 

 mixture should be carefully "spaded" immediately after 

 "placing" — on the side next to the form where the finished 

 concrete will be exposed to view-. By "Spading" is meant 

 the working of a spade or beveled board between the con- 

 crete and the side of the form, moving it to and fro, and 

 up and down. This forces the large stones away from the 

 boarding, or form, and brings a coating of mortar next 

 thereto, thus making the face of the work present an even, 

 smooth appearance. 



Green concrete should not be exposed to the sun until 

 after it has been allowed to set for five or six days. Each 

 day during that period the concrete should be wet down 

 by sprinkling water on it, both in the morning and after- 

 noon. This is done so that the concrete on the outside 

 will not dry out much faster than the concrete in the 

 center of the mass, and should be carried out carefully, 

 especiallv during the hot summer months. Old canvas, 

 sheeting, burlap, etc., placed so as to hang an inch or so 



a\\a\- from the face of the concrete will do ver\- well as a 

 protection. Wet this, as well as the concrete. ' Often the 

 concrete forms can be left in place a week or ten days; 

 this protects the concrete diu-ing the setting-up period 

 and the above precautions arc then unnecessary. 



It may be well, in summing u]), to emphasize the follow- 

 ing points : 1. The materials mu.st be perfectly clean. 

 2. The mixing must be in proportions carefiflly de- 

 termined. 3. The mixture must be used while absolutely 

 fresh, (jood results cannot be obtained unless you use a 

 good cement, nor will the work be at its best unless care 

 is taken in the selection of clean sand and clean stone. 



Among the uninitiated, there is an all too prevalent idea 

 that anything is good enough for the making of concrete. 

 Some will tell you that sawdust, shavings, mud, clay, etc., 

 will do tn complete the mixture, hut the absurdit\- of this 

 notion will very soon become evident to anyone who 

 neglects the precautions which lia\e been .-ihovc jxiinted 

 out. 



( To be continued. ) 



DOMESTICATING THE MALLARD DUCK. 



B\ L. I'. Ji:xsi;x. Missoiki. 



Perhaps one of the most interesting sights to be 

 witnessed, at any time, at Mr. August A. lUisch's 

 Grant's farm, near St. Louis, Mo., is the large number 

 of mallard ducks. 



Several years ago a few diimesticated birds were 

 secured, and the flock now numbers several hmidred. 

 It is a beautiful sight to behold when several of them 

 take wing and circle over the property, eventually 

 alighting on one or the other of the watercourses or 

 lakes on the place. 



At present the female may be found on stumps of 

 eild trees, or in the underbrush near the water, hatch- 

 ing her brood of youngsters. Many of them are also 

 to be seen with their brood of little ducklings swim- 

 ming on the water, busily devouring any insect that 

 may come within their reach. These little ducklings 

 are very interesting to observe, as they are very active 

 and rapid in their movements, darting in all directions 

 as quick as a flash, vet remaining close to the mother 

 bird. 



The nesting females are so tame that you may 

 almost step on them before they attempt to leave the 

 nest, and in most cases, they permit you to touch 

 them with your hand. 



They are regularly fed with wheat and other grain, 

 and remain on the place all year. They require very 

 little care and protection. They are never pent up, 

 and seldom take advantage of the house put up for 

 their protection. 



The mallard duck seems to create confidence among 

 other species of wild ducks, which h,i\e become regu- 

 lar visitors to the ]:)lace, and permit you to approach 

 very close to them before they alight. 



'i"he accompanying illustration shows a small group 

 of them in their favorite element. 



{See illustration, page 319.) 



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I r^UR QUERIES AND ANSWERS column is | 



j omitted from this number due to lack of space. | 



I It will appear in the August number. Have you any 1 



I inquiries to make? | 



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