_Provisions._--A little stock of rice, for it takes time to get accustomed to the food of the country, which is chiefly of plantain and manioc. I had some flour, for I intended to make my own bread on the coast. I had coffee--coffee and quinine I never was in want of. I had two little filtered coffee-pots. The forest was so full of malaria that very seldom I woke without a headache in the morning, and the first thing I did was to make a cup of coffee; after drinking it my headache went away. Do not forget to take salt with you, for salt becomes priceless in the interior, and to be without salt is a great privation. A thorough explorer who goes in wild and unknown regions must find his way by astronomical observation, so that he may be able to present a reliable map on his return. This part of the outfit alone is quite an item and somewhat expensive, for not only must you have instruments to find out your longitude and latitude, but you must have others to give you the height of the country, the temperature in the sun and in the shade. You must have a number of watches; these are absolutely necessary in order to know your longitude. Never mind if they do not go very well; but you must time the space of time by minutes and seconds between the observations. _Scientific instruments._--Five watches; one I wore at home, and four were specially made for observation. They were large, and of silver, and made especially for me. The hands were very black, and so were the hands marking the seconds, so that the minutes and seconds could be distinctly seen. If my watches had stopped, I should not have been able to find my longitude--that is, to know how far east or west I was. Four sextants; one for taking altitudes of the stars and planets, in connection with a lunar (a lunar is to find the distance between the moon and one of the eleven lunar stars), to an artificial horizon--that is, an improved iron trough which I filled with quicksilver kept in an iron bottle, to imitate the sea; on this the stars were reflected, and with the aid of my sextant I could see when they were on the meridian. Three thermometers for knowing the height of the country by boiling water; two thermometers to know the heat of the sun, marked to 230°; three other thermometers, graduated for Fahrenheit and Centigrade. (I wish we might give up the Fahrenheit, for it has no scientific basis.) Three aneroids to know approximately the height of the country while on the march, to avoid making observations by boiling water, which takes so much longer time; two telescopes; four compasses; universal sun-dial; two magnifiers or reading-glasses, to find out quickly the degrees, minutes, and seconds marked on the sextants; one extra bottle of mercury, containing seven pounds, for artificial horizon; rain-gauge, to find out the amount of rain falling in the country; scale; two protectors, circular, with compass rectifier; paper, slates and slate-pencils; nautical almanacs