By land this would be about twenty-two miles, to be done, said my uncle, in two days.
But when he learnt that the Danish mile was 24,000 feet long, he was obliged to modify his calculations and allow seven or eight days for the march.
Four horses were to be placed at our disposal - two to carry him and me, two for the baggage. Hams, as was his custom, would go on foot. He knew all that part of the coast perfectly, and promised to take us the shortest way.
His engagement was not to terminate with our arrival at Stapi; he was to continue in my uncle's service for the whole period of his scientific researches, for the remuneration of three rixdales a week (about twelve shillings), but it was an express article of the covenant that his wages should be counted out to him every Saturday at six o'clock in the evening, which, according to him, was one indispensable part of the engagement.
The start was fixed for the 16th of June. My uncle wanted to pay the hunter a portion in advance, but he refused with one word:
"_Efter,_" said he.
"After," said the Professor for my edification.
The treaty concluded, Hans silently withdrew.
"A famous fellow," cried my uncle; "but he little thinks of the marvellous part he has to play in the future."
"So he is to go with us as far as --"
"As far as the centre of the earth, Axel."
Forty-eight hours were left before our departure; to my great regret I had to employ them in preparations; for all our ingenuity was required to pack every article to the best advantage; instruments here, arms there, tools in this package, provisions in that: four sets of packages in all.
The instruments were:
1. An Eigel's centigrade thermometer, graduated up to 150 degrees (302 degrees Fahr.), which seemed to me too much or too little. Too much if the internal heat was to rise so high, for in this case we should be baked, not enough to measure the temperature of springs or any matter in a state of fusion.
2. An aneroid barometer, to indicate extreme pressures of the atmosphere. An ordinary barometer would not have answered the purpose, as the pressure would increase during our descent to a point which the mercurial barometer  would not register.
3. A chronometer, made by Boissonnas, jun., of Geneva, accurately set to the meridian of Hamburg.
4. Two compasses, viz., a common compass and a dipping needle.
5. A night glass.
6. Two of Ruhmkorff's apparatus, which, by means of an electric current, supplied a safe and handy portable light 
The arms consisted of two of Purdy's rifles and two brace of pistols. But what did we want arms for? We had neither savages nor wild beasts to fear, I supposed. But my uncle seemed to believe in his arsenal as in his instruments, and more especially in a considerable quantity of gun cotton, which is unaffected by moisture, and the explosive force of which exceeds that of gunpowder.
 In M. Verne's book a 'manometer' is the instrument used, of which very little is known. In a complete list of philosophical instruments the translator cannot find the name. As he is assured by a first-rate instrument maker, Chadburn, of Liverpool, that an aneroid can be constructed to measure any depth, he has thought it best to furnish the adventurous professor with this more familiar instrument. The 'manometer' is generally known as a pressure gauge. - TRANS.
 Ruhmkorff's apparatus consists of a Bunsen pile worked with bichromate of potash, which makes no smell; an induction coil carries the electricity generated by the pile into communication with a lantern of peculiar construction; in this lantern there is a spiral glass tube from which the air has been excluded, and in which remains only a residuum of carbonic acid gas or of nitrogen. When the apparatus is put in action this gas becomes luminous, producing a white steady light. The pile and coil are placed in a leathern bag which the traveller carries over his shoulders; the lantern outside of the bag throws sufficient light into deep darkness; it enables one to venture without fear of explosions into the midst of the most inflammable gases, and is not extinguished even in the deepest waters.