410 



December, 1916. 



Amarican Vee Journal 



ago solved this question by the use of 

 some 70 thermometers placed in the 

 winter in different parts of the hives. 

 His results agree in general with those 

 of Dr. Phillips, but he became convinced 

 that his conclusions could not be quite 

 exact on account of the disturbance 

 produced by inserting or removing the 

 instruments, and for that reason he did 

 not publish his investigations. But he 

 solved another question, that concern- 

 ing the relation between the entrance 

 and the colony temperature, in winter. 

 He selected .50 hives, half of which 

 were allowed an opening of 200x15 

 millimeters (8x>8 inches), and the 

 other half 50x8 m.m. (2x.5-16 inches). 

 Each entrance was supplied with a 

 thermometer and the temperature noted 

 each day, morning and evening. The 

 result was entirely in favor of the large 

 opening. According to this experi- 

 menter the large opening produces the 

 following advantages: 



1. The unhealthy contaminated air 

 from the breath of the bees is not re- 

 tained. 



2. The combs remain dry. 



3. The bees are quieter. 



4. The stores, whether sealed or un- 

 sealed, remain healthy. 



In addition to this, the French 

 savant, Gaston Bonnier, made experi- 

 ments, to ascertain whether, to econo- 

 mize the heat of the colony, it was 

 better to use a dummy-board or whether 

 a dry comb would render the same ser- 

 vice. He found no difference between 

 the two. This should not astonish us, 

 since the illustrious Tyndall has recog- 

 nized that beeswax is the most imper- 

 vious substance to radiating heat. 



According to Dr. Phillips, the tem- 

 perature of the brood-nest is between 

 95 and 97 degrees, but if there is no 

 brood, it may go down to 67 degrees, 

 providing the outside temperature does 

 not go below that point. As soon as 

 this happens the temperature of the 

 cluster rises because the bees, incon- 

 venienced by the cold, draw towards 

 the center. The colder the weather 

 becomes the more compact the group, 

 and while the outer bees fill the space 

 between the combs, the other bees 

 occupy the inner empty cells. In 

 this way the bees on the outer edges 

 form a dense covering for the protec- 

 tion of the colony against the cold. 

 The greater intensity of the cold causes 

 a diminishing of the size of the cluster 

 which gets nearer and nearer to a 

 spherical shape, this shape giving the 

 largest possible capacity in proportion 

 to its surface, and for that reason 

 allowing the least deperdition of heat. 



The cluster, being changeable at 

 will, can readily adjust itself to the ex- 

 terior conditions. If the temperature 

 lowers, the surface of the cluster and 

 the loss of heat both decrease; at the 

 same time the cluster is more dense 

 and the inner heat thereby increases, 

 since there is less occasion for the 

 heat to escape. When the temperature 

 again rises, the cluster expands, and 

 the heat again escapes more readily, 

 thus lowering the inner heat. The 

 dense covering of live bees is less 

 compact and the outer air pervades the 

 cluster more readily. That is the ex- 

 planation of Dr. Phillips' observation, 

 " When the outside temperature begins 

 to rise the cluster temperature drops 

 slowly only to be increased when 



the outside temperature again drops." 

 The following table indicates the 

 enormous value which a condensed 

 spherical cluster offers for the economy 

 of heat in winter: 



Differ Per- 

 Combs Surface in centimeters ence cent 



Reduc'n from 6 to s from 1465 to I0I7 448 306 



5 to 4 " 101; to ii^i IDIi ^(10 



" ii to 4 " un; to i'=,i Hii 5^ 



The cluster does not always form in 

 exactly a spherical shape. Sometimes 

 it is difficult for the bees to withdraw 

 from one comb to another. The bees, 

 however, withdraw from the outer 

 combs, usually, early in the season, but 

 assume the sphere shape only when the 

 cold becomes intense. 



The fact that the bees occupy not 

 only the space between the combs, but 

 the empty cells as well, and thus make 

 the sphere as small as possible, indi- 

 cates by what marvelously simple 

 means Mother Nature provides the 

 safety of the bees. 



But why are the bees active within 

 the cluster and thus increase the pro- 

 duction of heat ? Why are they less 

 active when the temperature is high 

 and more active when it is low ? Are 

 they informed of the need of activity 

 to sustain their existence ? I think 

 not. The bees in the center of the 

 cluster are warm and cannot realize 

 the existing conditions of cold on the 

 outer rim. But they aie in viciated air, 

 and the want of pure oxygen drives 

 them to activity. They get rid of the 

 foul air by action, night and day. It is 

 the need of renewal of this air which 

 compels them to act in more lively 

 manner as the cold increases and the 

 cluster becomes more compact and 

 more impervious to an air current. Air 

 is needed and the entire cluster must be 

 aerated. In summer, air is needed to 

 cool the inside of the hive and to help 

 evaporate the honey. In winter a suffi- 

 cient amount of air is needed to re- 

 move the breathed atmosphere and re- 

 place it with fresh oxygen. It is also 

 necessary that the evaporating mois- 

 ture be enabled to escape so as not to 

 annoy the bees or disturb their comfort. 

 The necessity of a compact cluster 

 has been fully recognized as guarantee- 

 ing the life of the bees against extreme 

 cold. But the relation between the 

 production of heat and the consump- 

 tion of honey has not been touched. 

 The general idea is that this consump- 

 tion corresponds to the increase or 

 decrease of cold, that it increases with 

 a lower temperature and decreases with 

 the higher degree. But this is not ex- 

 act. The daily weighing of colonies 

 does not prove it. Here is an example : 

 Both the German and Swi«s Beekeep- 

 ers' Associations practice these weigh- 

 ings daily in the summer and every ten 

 days in the winter. One winter the 

 November and December weighings 

 showed the following comparative con- 

 sumption and temperature: 



[<ov. consamption Temper- Dec. consumption Temper- 



ature store 



140 grams ^i<> 60 grams iH 



70 " 21 2 00 " 21,1 



310 " 24 8 no " 15.8 



November mean consumption. 173 3 grams: 

 mean temperature. 23 3. 



December mean consumption. 76.(1 grams; 

 mean temperature. 18 6. 



The consumption therefore decreased 

 while the temperature lowered. 



It results from this that cold weather 

 economizes the stores and becomes the 



ally of the beekeeper. How can we 

 explain this ? We have shown that 

 during extreme cold weather in the 

 outer shell bees move but little, and 

 this inactivity reduces the need of food 

 consumption. They economize on their 

 food because of the economy of their 

 physical strength. In a mild winter it 

 is the reverse. The flights are numer- 

 ous and the stores disappear and dimin- 

 ish the hopes of the apiarist for the 

 following harvest. The deduction we 

 draw from this is that the beekeeper 

 must see to it that his bees be dis- 

 turbed as little as possible during the 

 winter, for their benefit and his own. 

 Zurich, Switzerland. 

 [Our readers will remember our cor- 

 respondent as the translator of Ber- 

 trand's "Conduite du Rucher " from 

 French into German. Mr. Spuehler is 

 not only a good beekeeper and a stu- 

 dent, he is also a polyglot, since he 

 reads and writes three or_ four lan- 

 guages. We mentioned our visit with 

 him at Zurich, in our " Notes from 

 Abroad " in September, 1914. He has 

 contributed to our Journal several 

 times, since. 



The principal question upon which 

 Mr. Spuehler insists is the increase of 

 heat of the cluster caused by its greater 

 or less compactness A similar state- 

 ment will be found in an article by Mr. 

 J. E. Hand, a practical beekeeper who 

 is well known to our readers, on page 

 305 of the September number. 



Although Dr. Phillips, in the wonder- 

 ful report made by him in Bulletin No. 

 93, shows that the cluster becomes 

 more compact, with the decrease of 

 temperature, he gives us to understand 

 that the " source of the heat of the 

 cluster must, of course, be the oxida- 

 tion of the food consumed by the bees " 

 (page 15). That this heat is better kept 

 by the compactness of the cluster is 

 evident. Phillips also says: "That 

 higher temperatures may be produced, 

 greatly increased muscular activity is 



required bees fan to heat the 



cluster in winter as well as to cool the 

 hive in summer." 



But the explanation given in the 

 above article, by Spuehler, that the bees 

 fan within the cluster to secure pure 

 oxygen "because the air is needed" 

 within this compact cluster, must be 

 correct. 



A question which Mr. Spuehler raises 

 is that of the connection between con- 

 sumption and temperature. He indi- 

 cates that the low temperatures require 

 less consumption. We acknowledge 

 that we have been and are still of a 

 totally different opinion. Although 

 Bulletin No. 96, on "The Temperature 

 of the Colony," by our friend Prof. 

 Burton N. Gates, of Massachusetts, 

 shows that "the rate of consumption of 

 stores exhibits relatively constant de- 



