As I have been frequently asked to explain the utility of ventilation in a hive or colony of Bees, so have I as frequently been asked, sometimes with civility and politeness, sometimes jeeringly and in contempt,--"What has the thermometer to do with Bees?" I answer--We shall see presently; and I trust, see enough to convince the veriest sceptic on the subject, that the thermometer is an instrument that is indispensably necessary in the management of Bees according to my plan. Such inquirers might as reasonably ask what the mainspring of a watch has to do with the movements of that machine? Without the mainspring the watch would not work at all; and without the thermometer we cannot ascertain with any degree of accuracy the interior temperature of the hive; the knowledge of which temperature is of the utmost consequence in the humane management of Honey-Bees. The thermometer is the safest, if not the sole guide to a scientific knowledge of their state and works. To ventilate an apiary or colony of Bees, when their interior temperature is under 60 degrees, would be ruinous to them,--because contrary to the prosperous progress of their natural labours. From upwards of fifteen hundred observations in the summer of 1825, I am fully satisfied on this point. Their nature is to keep up at least that, and sometimes a much higher, degree of temperature by their indefatigable labours; and as the temperature of the hive rises, so does it invigorate and encourage an increase of population, as well as an increase of their treasured sweets. As the hive fills, so will the thermometer rise to 120 and even to 130 degrees, before these worthies will by over-heat be forced to leave their wealthy home. When the thermometer is at the above height, these wealthy colonists will have arrived at the highest state of perfection,--wealthy indeed, every store-house being filled nearly to suffocation with their abundant treasures, and they, as it were, petitioning the observer of their too-limited store-house for a fresh room. Thus circumstanced then give them a fresh room,--accommodate them with such a store-house as either of my collateral-boxes will and is intended to afford them. _Force them not to warm:_ an emigration from a prosperous colony of half its population cannot fail of being very disadvantageous, both to those that emigrate, who must necessarily be poor, and to those that remain, be they ever so industrious, or ever so wealthy. When you discover your thermometer rising rapidly, and, instead of standing, as it generally does in a well-stocked colony, at about 80 degrees, rising in a few hours to 90, and perhaps to 96, or even to 100, you may conclude that ventilation is _then_ highly necessary. The more you ventilate, when their temperature gets to this oppressive and dangerous height, the more you benefit the Bees labouring under it; for when they find a comfortable temperature within, they enjoy it, and will proceed to fill every vacant comb.