SOME EARLY THERMOMETERS EARL H. BROWN Antiorh College. Yellow Springs, Ohio
T
HE following is part of a cullection of d r a w i n g s of early t h e r m o m e t e r s f r o m the t i m e of Galileo d o w n to Fahrenheit. Inasmuch as there are a v a i l a b l e s e v e r a l scholarly treatises and shorter essays on the early history of t h e
thermometer, t h i s p r e s e n t a t i o n deals only w i t h the i n s t r u m e n t s fie7 se. The plates are arranged as well as possible to s h o w the e v o l u t i o n of the instrument.
TBzi Piale ?nor $i.oiurrd from T k r Edgor Faits S r n d h .Mnnni.ial Coll,~ilio,i in !he Hislory of Chemirlry. L'niurrsiis of Penizisivonio
This plate is from "A new method df'chemistry" translated from the original Latin of Dr.' Boerhaave's "Elements Chemiae . . ." bv Peter Shaw. London. 1741. No uarticular &scription of these thermometers is given in the iext. ~
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PLATE111 THIS INSTRUMENT WAS DEVISEDBY SANCTORIUS JUSTIPOLITANUS, PROFESSOR OF TXEORETICAL MEDICINEAT PADUA SHORTLYAPTER GALILEO:~ TIME
This sketch might well represent the subject of the following description': "He [Galileo] took a glass bulb, about the size of a hen's egg, to which was attached a tube approximatelv two mans in leneth and of the diameter of a straw. He then heated the bulg with his hands and inverted i t so that the tube was plunged into a vrsscl hencath. As soon as the air in the glohc l w ~ a n11, cool. ~hccwalcr rose l o more than a anan ahow the Iwcl of the liauid in the dish. Galilri ernpluyl.rl !hi.; phenomenon in the conilruction of an i n r r w mmr for invrstigating the degrrc of heat anrl cold " The prubsblr dntc of this experiment is l t i 1.1.
I t was used as a clmical thermometer. The bulb was heated and the open end placed in s vessel of colored liquid. When the bulb cooled, the liquid rose to a certain height in the tube. The patient then held the bulb in his mouth "for ten pulse beats" which caused the liquid to descend the tube thus indicating the temperature Pl& nf1er Bwckhardl, "Die Erfrndung dcr Thcrmomrlrrs und G~rloliungi n I7 Johrhundcrl."
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IF. B m c p a m r , "Die Erfmdndunp des Thermometers und seine Gestaltuug in 17 Jahrbundert," 1867. This and subsequent quotations from Burckhardt are from an unpublished translation by PROFESSOR E.H. JOHNSON. Kenyon College.
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THE PLATE SHOWSAN AIR THERMOMETER DEKIRCHERI N 1643 SCRIBED BY ATHANASIUS The air when heated in the bulb fxces the liquid upward in the tube. This instrument had one advantage in thst it was easily lunged into a liquid, a thing whicS was difficult with some other farms. .
I N THE EARLY DAYS OF THE THERMOMBTER. THERE WAS CONSIDERABLE EFFORT TOWARD IMPROVEMENT w n x o u r A CLEARUNDERSTANDING This is an instrument described in 1644 by
of the air in the large b i l b cause the movement of a short column of liquid in the stem. This thermometer was thought to be more sensitive than its predecessors.
DALENCBCONSIDERSTHE THERMOMETER %OWN I N THIS A CONSIDERABLE IMPROVEMENT IN DESIGN OVER PLA~E THATOF PLATEI As examination shows this is a one-piece instrument while that of Plate I consists of two parts. Bulb B contains air, while about half the stem A A and bulb E contain a colored liquid. Bulb E is open t o the atmosphere.
"A is a hollow copper sphere of about the size of the receiver on an air pump. BC is a copper tube about an inch in diameter, extending from the sphere for about seven yards. Attached to this is a second copper tube into which is poured spirits of wine, the quantity depending on the size of the tube. In this tube is placed a smaller tube of of a yard brass, and about long, having been previously loaded with small shot until its specific gravity was the same as that of the liquid. To this little piston is attached a waxed thread EM, which passes out of the tube. over a little ~ u l l e v F, and has a t its other 'end H little f i g u r e a n angel or a little naked boy-which points to the tube with its finger. The two tubes are inclosed in a wooden case so as not t o be visible, and the onlooker is shown a trick. The little figure points with its finrer t o the dearees markinr t h e temperature.- There is valve H in one side of the copper sphere, which the inventor calls the "nombril" of the sphere. From this opening air is removed by appropriate apparatus which is connected with a n air oumo &tiithe figure hangs in the proper place. If one does notknoiv the proper position, let him draw the air out when the cold misty nights come on, for then the figure must hang about half way up. Besides, practice brings improvement in everything. The discoverer of the Magdeburg experiments has this sphere hanging on the wall of his house where the sun never shines. I t is painted blue, decorated with gilt stars and bears the:superscription: Mobile Per9etuum."
Section A F of the stem is evacuatgd. Mercury fills the tube from F to C. Bulb D contains air and 's closed a t the upper end. (r This thermometer is described by DalencC and Burckbardt.
Bulb C contains air. A column of water extends from D to the middle of bulb B. A column of mercury extends from the center of B well into A . The mace in A above the mercurv is evacuated. ~ u b i ncompared his thermometer with one of the Florentine instruments and found the apparent expansions for a certain increase in temperature to be in the ratio of 216 t o 4.
" A A is a g l m tube which in the completed instrument is closed a t both ends. I t is about five inches long and har, an internal diameter of about four lines. BB is a smaller glass tubeinside the tube A A . In order to assemble the thermometer, the smaller tube which is closed a t one end, is filled with mercury. "The mcrcury-filled tube BB is then held with the open end umermost and sealed within A A in such a manner that one end of BB remains open "This done, the instrument is suddenly inverted. The mercury heretofore contained in BB is now free to flow and bdnn heavier thsn the air of A A flows art wav into A A compressing the air contained therein and causinb a ~ a r t i a l vacuum in BB."
PLATEX I
THUSFAR SITOWN,TEE EXPANDING MATERIALHAS BEENAIR PEMAPS THE F m s r RECORDOP m& USE OP A LIQUID AS EXPANDINGMATERIALI N A THERMOMETER IS THE FOLLOWING "I1 y a divenit6 de thermoscopes ou thermomStres. a ce aue je vovs: ce aue vous en dites ne peutconve& a" mi&,qui n'est plus rien qu'une petite phiole ronde, ayant le w l fort long et deslib. Pour m'en s e ~ r je, la mets au s o l d , et parfois B la main d'un fkbricitant, I'ayant toute remplie d'eau, fors le col; la chaleur dilatant l'eau fait qu'elle monte; le plus ou le moins m'indique l a chaleur grande au petite." ) The above quotation is from Burckhardt and is part of a letter from Jean Rey to Msrin Mersenne, . . , T h e sketch was made from the above description, Whether or not the upper end of the stem was closed is not known. The probable date of this instrument is ,1631. I N THE INSTRUMENT8
PLATEXI11 IN DALENCB.~ LITTLEBOOR THIS IS ONEOP SEVEULFOUND SFI~WINGT m s PARTICULAR TYPE OP INSTRUMENT
The stem is about three feet long. that large bulbs be flattened.
Dalenc.6 recommended
part of the wale marked 20 when the insrrum~ntis packed in ice and snuw- and not higher thsn o(1 drgrrrs in extreme summer hear. . . . The tulw i r corrfllllv m a d w a r d -its~ rnttrr length being divided into ten equal pa;t
