56 
THE VOYAGE OF H.M.S. CHALLENGER. 
CO AN US’ 
SolNDlNO 
Apparatus. 
I’UKHI.IUlV 
Apparatus. 
ctssful. These rude attempts are not devoid of interest, since they showed progress 
in the knowledge of the physico-chemical and biologicai phenomena of the sea. 
From the most remote ages soundings have been made by hand with a plummet. 1 
Varenius pointed out, during the seventeenth century, the difficulties that beset deep-sea 
soundings. 2 But, long before the time of this famous geographer, endeavours were made to 
-rmount the difficulties attending direct soundiug by substituting for the sounding-line 
and lead an apparatus, the original idea of which is due to Cardinal Nicolaus Cusanus. 3 
Generally speaking, this apparatus consisted of two bodies, one lighter than water the 
other heavier, so connected that when the heavier body touched the bottom the lighter 
one became self-detached and rose to the surface alone, the depth being calculated from 
the time required for the apparatus to sink to the bottom and the float to rise again to the 
surface Such is the principle on which the first bathometers with self-acting floats were 
• onsrructed. According to Poggendorf, 4 the bathometer of Cusanus consisted of a hollow 
phere, having a weight attached by means of a hook, -which became detached on the 
weight touching the ground ; the weight was intended to carry down the sphere with a 
certain degree of velocity.® 
About a century later Puehler 6 took up Cusanus’ idea, and devoted the 44th chapter 
1 II< rodotus says : “ On approaching Egypt by sea, when you are still a day’s sail from the land, if you letdown a 
sounding line you will bring up mud, and find yourself in eleven fathoms of water, which shows that the soil washed 
down by the stream extends to that distance ” (Herod, ii. 5). 
1 In 1671 he wrote : — “Nautae profunditatem explorant bolide, cujus materia est plumbea, figura pyraraidalis, 
j'i ,ndu s duodecim circiter librarum, si funis sit trium vel plurium libra rum, qualis suflicit ad ducentas perticas, etsi alii 
n-iuirant bolidem plurium librarum, possunt tamen inhac observatione decipi, si funus ab aquae vorticibus et undis 
abreptus non perpendiculariter sed oblique descendat” (Varenius, op. cit., lib. i. prop. vi. p. 144). 
* 1401-1464. t * Poggendorf, Geschichte der Physik, p. 1 1C, Leipzig, 1879. 
■ In Cusanus work : De Staticis experiments fragmentum, which is added to Vitruvius’ edition of Bale, 1543, 
a . !,u!iiciai. a king to a philosopher says : — “Cum plumbo fieret formato ad mstar lunae octodierum, ita tamen 
: c rmi unum sit ponderosius et aliud levius, et in leviori pomum aut aliud leve tali instrumento appendatur 
qu< i pluml>o in fundum pomum trahente et primum cum ponderosiore parte terram tangente et se sic successive, 
inclinante pomum dc cornu Uberatum sursum revertatur.” 
S- G nther, Lehrbuch der Geophysik, Bd. ii. p. 329. We give here the original text of Puehler relating to 
tbi- apparatus : — “ Erstlicb solt du ein rund hole Kugel von Metall, als von Zyn oder kupffer, aufl' das allerdinnest 
» hho i ii i dermassen gantz gemacht machen, dass kein trdpflin Wasser darein gehe, wann die Kugel, als du horen 
wir \ i: 1 Wu. r ge nkt wirdt unud soil ein orlein von einem runden messenen Drat darauff gelotet sein. Damach 
r. mm ein vierecket ibengcschlagen Plech, auch von Metall gemacht, welches lenger, dann es breit iat, soli sem : unnd 
in • r* 1 r leng’ breiter denn an dem udem : undsol) auff der einen lengen seitten bey den breitten ort des plechs 
♦•it "11 r i • :•■!! at •• 1 ft.t sich geschosseu, und zuruck gebogen haben : an dem andern ort diser seitten, soli es einen fur 
. 1 : !< . , bal -n, de» Rich auch von dem plech zuruck dermassen herablasse : damit das plech, wenn es mit der hohlen 
K el end t v r It, und der fu-s den boden oder den grund in dem wasser erraichet, fiir sich sinck, unnd sich mit dem 
Ati.-fl in* : m rleinder Kugel ziech, unnd die Kugel also kimne von dem plech mussig und ledig werden. Gestalt und 
f rrn !> ♦ pb ■ i und der Kugel bantu in nachfolgender Figur. Das plech aher soli an dem fuss also schwiir sein, wenn 
d* r f ' 1 1 • i »• tn plech ni< ht Mure, la • cr allein die Kugel rincklich gen boden kan zieben. Darnach soltu Direin 
<r ■ • i - n m ichcn, das mit h li, sunder breit, wie tin erden hand beck, wol gebrennet, und glasiirt sey : und 
r; . i : • -i it It"! - i, ein kb in* lochlein hah: discs Instrument solt Du zuvor also zubereiten und probiereu, an dem 
ort <l. ..-<■• oder a ii i- du dan I ii .trument widerumb wnist auss dem wasser zu gewinnen, und die tiefie des wassers 
mu eiin-r iha*», ah ctn< m pleysenckel etlicher klafter lang kanst abmessen, thu das plech mit seinetn angel in das 
orb ;n i t Ki un i i ilt die Kugel in der hand, und d. plech an die Kugel liange, und lasse daz plech in daz wasser 
