THIMBLE 995 



Chemistry. 1. The evaporating, boiling, fusing, melting, subliming, and congealing 

 points of the principal solids and liquids in chemistry, from 12 to 374 Fahrenheit, 

 from 11 to + 190 Centigrade and from 9 to + 152 Reaumur, including the 

 boiling points of the saturated solutions of numerous salts, and the melting points of 

 a large number of alloys. 



2. The temperature for fermentation of various kinds, malting, putrefaction, etheri- 

 fication, and other chemical processes. 



3. The boiling points of alcohol and acids of various specific gravities, with the 

 respective densities of their vapours. 



4. The pressure or elastic force of the vapour of water, alcohol, oil of turpentine, 

 and ether, at various temperatures. 



5. The temperatures, with the corresponding pressures, required for the liquefaction 

 of the gases. 



6. The temperature for the explosion and ignition of fulminating and combustible 

 substances. 



Physiology. 1. The maximum degrees of natural and artificial heat, and minimum 

 degrees of cold, borne by man and animals. 



2. The temperature of the body in man, mammalia, birds, reptiles, fishes, and 

 insects. 



3. The temperature at which hybernation takes place in certain animals. 



4. The temperature for the germination of seeds, incubation, the artificial hatching 

 of the ova of birds, fishes, and insects. 



5. The temperature for the growth of the sugar-cane, date, indigo, cotton-tree, and 

 for the cultivation of the vine. 



6. The temperature for warm, tepid, and vapour-baths ; the vapour-baths of Russia 

 and Finland. 



THERMOMETER, Self -registering, by Photography. The first person who in * this 

 country proposed to apply photography, and actually did apply it, as a means of 

 registering the movements of the mercury in the thermometer and barometer, and 

 also for registering the variations in the magnetic intensity, was Mr. Thomas B. 

 Jordan, at that time Secretary to the Eoyal Cornwall Polytechnic Society. The 

 results of this gentleman's methods and the description of his plans will be found 

 in the Sixth Annual Report of the Royal Cornwall Polytechnic Society for 1838. 



Mr. Eonalds, of the Kew Observatory, also devisee! an arrangement for employing 

 photography as the means of registering meteorological inventions, and subsequently 

 Mr. Charles Brooke perfected a method which is now generally adopted. 



THERMOSTAT is the name of an apparatus for regulating temperature, in 

 vaporisation, distillations, heating baths or hothouses, and ventilating apartments, 

 &c. ; for which Dr. Ure obtained a patent in the year 1831. It was, in fact, a diffe- 

 rential thermometer, similar in construction to Brady's metallic thermometer. 



THIALDINE. C I2 H 13 NS 4 (C 6 H 13 US 2 ). A curious alkaloid, formed by the 

 action of sulphuretted hydrogen on aldehyde ammonia. 



THIEVES' VINEGAR. (Lc Vinaigrc des quatre Voleurs, Fr.) See AROMATIC 

 VINKGAB. 



THIMBIiE. (De a coudre, Fr.; Fingerhut (fingerhaf), Ger ) This is a small trun- 

 cated metallic cone, deviating little from a cylinder, smooth within, symmetrically 

 pitted on the outside with numerous rows of indentations, which is put upon the tip of 

 the middle finger of the right hand, to enable it to push the needle readily and safely 

 through cloth or leather, in the act of sewing. This little instrument is fashioned in 

 two ways : either with a pitted round end, or without one ; the latter, called the open 

 thimble, being employed by tailors, upholsterers, and, generally speaking, by needle- 

 men. The following ingenious process for making this essential implement, the con- 

 trivance of MM. Rouy and Berthier, of Paris, has been much celebrated, and very suc- 

 cessful. Sheet-iron, one twenty -fourth of an inch thick, is cut into strips, of dimensions 

 suited to the size of the intended thimbles. These strips are passed under a punch- 

 press, whereby they are cut into disks of about 2 inches diameter, tagged together by 

 a tail. Each strip contains one dozen of these blanks. A child is employed to make 

 them red-hot, and to lay them on a mandril nicely fitted to their size. The workman 

 now strikes the middle of each with a round-faced punch, about the thickness of his 

 finger, and thus sinks it into the concavity of the first mandril. He then transfers 

 it successively to another mandril, which has five hollows of successively increasing 

 depth ; and, by striking it into them, brings it to the proper shape. 



A second workman takes this rude thimble, sticks it in the chuck of his lathe, in 

 order to polish it within, then turns it outside, marks the circles for the gold ornament, 

 and indents the pits most cleverly with a kind of milling tool. The thimbles are 

 next annealed, brightened, and gilt inside, with a very thin cone of gold-leaf, which 

 is firmly united to the surface of the iron, simply by the strong pressure of a smooth 



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