242 



THE BEE-KEEPERS' REVIEW 



former it is almost always possible to 

 trace the source of the contaf^ion, while 

 the latter often appears in an apiary 

 several miles from other bees, and 

 in a manner that mi^ht be called 

 mysterious. 



There is one very important point 

 upon which both varieties are exactly 

 alike; they can be eliminated com- 



pletely from any apiarj' by shaking 

 off the bees and allowing them'^o%uild 

 new combs I was in one .apiary of 

 about 70 colonies, many of which .were 

 diseased last spring with b'jack'brood, 

 and all were "shook" except four col- 

 onies, and not a trace of the disease 

 could be found — combs and brood all 

 clean, bright and healthy. 



CEMENT MORTAR AND CONCRETE, 



Some Suggestions as to its Use in Build- 

 ings, Walls, Etc, 



There are probably some bee-keep- 

 ers who are thinking of this fall build- 

 ing a permanent bee-cellar, and the 

 question of what shall be used in build- 

 ing the walls is a serious one. In 

 many places concrete made of Portland 

 ce nent, sand and gravel will be the 

 most desirable for several reasons. It 

 is cheap and durable, and, if a few 

 suggestions are followed, the work can 

 be done by . unskilled labor. The 

 United States government has gotten 

 out a liulletin on the subject, and from 

 that I extract the following points: — 



Cemmt mortar is an intimate mix- 

 *':roof cement and sand mixed with 

 sufficient water to produce a plastic 

 mass. The amount of water will vary 

 according to the proportion and condi- 

 tion of the sand, and had best be de- 

 termined independently in each case. 

 Sand is used both for the sake of econ- 

 omy and to avoid cracks due to shrink- 

 age of cement in ^-etting Where great 

 strength is required, there should be 

 .it least sufficic!"''^^ cement to fill the 

 voids or air spaces in the sand, and a 

 sliirht excess is preferable in order to 

 Compensate for any uneven distribu- 

 tion in the mixing. Common propor- 

 tions for Portland cement mortar are 3 

 parts s^nd to one of cement, and for 

 nai iral cement mortar. 2 parts sand to 

 1 of cement. Unless otherwise stated, 

 materials for mortar or concrete are 

 considered to be proportioned by 

 volume, the cement being ligiitly 

 shaken in the measure used. 



A "lean" mortar is one having only 

 a small proportion of cement, while a 

 "rich" mixture is one with a large 

 proportion of cement. "Neat" cement 

 is pure cement, or that with no admix- 

 ture of sand. The term "aggregate" 

 is used todesignate thecoirse materials 

 entering into concrete — usually gravel 

 or crushed rock. The proportion in 

 which the three elements enter into the 

 mixture is usually expressed by three 

 figures separated by dashes — as. for 

 instance, 13 5 — meaning 1 part cement, 

 3 parts sand, and 5 parts aggregate. 



In mixing cement mortar it is best to 

 use a platform of convenient size or a 

 shallow box. First, deposit the re- 

 quisite amount of sand in a uniform 

 la^'er, and on top of this spread the 

 cetnent. These should be mixed dry 

 with shovels or hoes, until the whole 

 mass exhibits a uniform color. Next, 

 form a crater of the dry mixture, and 

 into this pour nearly the entire quan- 

 tity of water required for tlie batch. 

 Work the dry material from the outside 

 toward the center, until all the water 

 is taken up, then turn rapidly with 

 shovels, adding water at the same time 

 by sprinkling until he desired con- 

 sistency is iittained. It is frequently 

 specified that the mortar shall be 

 turned a certain number of times, but 

 a better practice for securing a uniform 

 mixture is to watch the operation and 

 judge by the eye when the mixing has 

 been carried far enough. In brick 

 masonry the mistake is frequently 

 made of mixing the mortar very wet 

 and relying upon the bricks to absorb 

 the excess of water. It is better, how- 

 ever, to wet the bricks thoroughly and 

 use a stifiF mortar. 



In securing sand for mixing mortar 

 or concrete, if it is possible to select 

 from several varieties, that sand should 

 be chosen which is composed of sharp, 



