I 1877 fik jeg til Foræring af Hr. J. Y. Buchanan, 
Challenger-Expeditionens Chemiker, et nyt Dybvandsther- 
mometer af en ejendommelig Construction, som han hav- 
de opfundet og prøvet paa denne Expedition, og hvilket 
han kaldte Kviksølvpiezometer.  Uagtet kortelig beskrevet 
af Hr. Buchanan), maa jeg dog her give en Beskrivelse 
af dette Instrument, da det var mig, navnlig i 1877, men 
ogsaa i 1878, til uvurderlig Nytte som Controlapparat for 
de Miller-Casella’ske Dybyandsthermometres Trykcorrec- 
tioner, foruden som et selvstændigt Dybvandsthermometer, 
der aldrig kom i Uorden, og som tillod en større Nøjag- 
tighed i Temperaturens Bestemmelse end de ældre Ther- 
mometre. 
Figur 1 viser Kviksølvpiezome- 
tret i halv Maalestok. Det er, som 
man ser, et Kviksølvthermometer, hvis 
Beholder Å er temmelig stor og ikke 
In 1877, Mr. J. Y. Buchanan, Chemist to the Chal- 
lenger Expedition, kindly presented me with a deep-sea 
thermometer, of a new and peculiar construction, devised 
by himself and tested on that Expedition, and which he 
calls the Mercury-Piezometer. Though briefly described 
by Mr. Buchanan,t I must here append a description of 
this instrument, since it proved in 1877, but also in 1878, 
of incalculable advantage for controlling the pressure-correc- 
tions of the Miller-Casella deep-sea thermometers, not to 
mention its use as an independent deep-sea thermometer, 
that never got out of order and which admitted of greater 
certainty and exactness in determining the temperature 
than any of the older instruments. 
Figure 1 represents 
cury-piezometer, half size. 
the mer- 
It; 18, 25 
will at once be seen, a mercury-ther- 
mometer, having the bulb Å com- 
beskyttet mod det ydre Tryk. Det | Ne D | paratively large and not protected 
i Millimeter paa selve Glasset ind- | against the outward pressure. The 
delte Thermometerrør er ombøjet og © stem, divided into millimetres on 
fyldt med rent Vand fra B til C, MAN the glass itself, is bent round and 
forresten med Kviksølv. Dets Ende al I filled with pure water from 'B to 
er aaben og udmunder i Koppen D, MENN nil C — for the rest, with mercury. 
der er fyldt med Kviksølv. Denne å ne Its end is open and dips into the 
Kop er kugleformet med en Hals, 35 ES cup, D, which is filled with mer- 
der omslutter Thermometerrøret. Et 37 2 eury. This cup is spherical in shape, 
Stykke Kautschukslange E fæster B- ar LBs with a neck encireling the tube of 
Koppen til Roret. For at give Van- 56-1 I 99 the thermometer. A piece of india- 
det Adgang til at trykke paa Kvik- 371 97 rubber tubing, E, attaches the cup 
sølvet i Koppen er Glasstangen eller | to the glass stem. That the water 
Glasrøret H stukket imellem Ther- may have free admission to press.upon 
mometerrøret og Kautschukslangen. the mercury m the cup, the glass 
En magnetisk Index I af samme rod or glass tube, H, is placed be- 
Slags som Indexen 1 Miller-Casella’s 
Thermometer, er indbragt 1 Vandet 
over Kviksølvet. Tallene paa Ska- 
laen betegne Centimeter. Instrumen- 
tet er, ligesom det neynte Thermo- 
meter, fæstet til en Ebonitplade og 
staar, naar det bruges, i et Kobber- 
hylster. Det er forfærdiget af Ca- 
sella i London. 
tween the stem of the thermome- 
ter and the india-rubber tubing. Å 
Magnetic Index, I, similar to the 
index the Miller - Casella ther- 
mometer, is introduced into the wa- 
ter above the mercury. The fig- 
on the scale indicate centime- 
As with the aforesaid ther- 
this instrument is made 
an ebonite plate, 
in 
ures 
tres. 
mometer, 
fast to and 
the whole rests enclosed withm a 
copper case. It was made by Ca- 
Instrumentet er saaledes constru- | 
eret, at dets Stand (den Aflæsning, 
der svarer til Kviksølvtoppen O) af- 
hænger saavel af Temperaturen som 
af Trykket. Dets Stand ved forskjel- 
lige Temperaturer under almindeligt 
Lufttryk bestemtes ved Sammenligning med Normalther- 
mometret. En Temperaturvariation af 1° C svarer omtrent 
' Proceedings of the Royal Society 1876. S. 163. 
Fig. 
sella of London. 
The instrument 
in such a manner, that its reading 
(the division that corresponds with 
the top of the mercury, C) depends 
alike on temperature and on pres- 
Its reading at different tem- 
is constructed 
sure. 
peratures under ordinary atmospheric pressure was deter- 
mined by comparison with the Standard-Thermometer. 
1 Proceedings of the Royal Society, 1876, p. 163, 
