114 Mr King on a New Self-registering Thermometer, 



Without noticing the utility of these instruments in facili- 

 tating various investigations of the natural philosopher, and 

 in regulating numerous processes in- the arts and manufactures, 

 suffice it to remark their use and importance in the practice of 

 the art of cultivation alone, as a recommendation to their more 

 general use. In every civilized community where that art is 

 encouraged, vegetables from distant parts are there transplant- 

 ed, and intended to grow and flourish within a few yards of 

 each other, which are not indigenous on account of the cli- 

 mate. Artificial arrangements must therefore be had recourse 

 to, and as the inequality of temperature alone forms in a 

 great measure the diversity of climate which is so manifest on 

 the earth's surface, these arrangements in Britain, in the same 

 and similar latitudes, consist in compensating for the deficiency 

 and fluctuations of the natural temperature of the atmosphere. 

 In the cultivation of those vegetables that are exposed to these 

 fluctuations, a correct daily register of the changes of tempera- 

 ture must be of vast practical utility to the cultivator. As they 

 point out the necessity, they may also suggest the means of 

 counteracting their effects. For those plants, again, which are 

 too delicate to reach maturity in the open air of a climate liable 

 to great and sudden meteorological vicissitudes, recourse must 

 be had to a covering of glass, and heat from fuel to produce 

 an artificial climate, of a more elevated and uniform tempera- 

 ture, and more congenial to their nature and habits ; hence the 

 construction of hot-houses, green-houses, and the like. Regis- 

 ter thermometers, under such circumstances, are also particu- 

 larly useful, for they not only point out slight changes in the 

 heat of the forcing-house to the person who may have the 

 charge, which guide him to regulate it accordingly, but they 

 also exhibit afterwards to the proprietor or overseer the extent 

 of those changes, thus forming a most correct and strict check 

 on the carelessness and inattention of his servants. 



The following description of one I beg to propose, I hope 

 will be understood. Of this thermometer the ]eg A, (Plate II. 

 Fig. 6,) is the same as a common mercurial thermometer, with 

 a scale graduated to any convenient range. The tube is turned 

 at top, and continued downwards, to form the leg B, parallel 

 to A, terminating in a point at C. Fig. 7, which is a 



