from Astrachan, p 99.
------------------------
#include <iostream.h>
#include "balloon.h"

// illustrates use of Balloon class
// balloon (guided by auto-pilot) ascends, cruises, descends

int main()
{
    Balloon montgolfier;
    int rise;               // how high to fly     (meters)
    int duration;           // how long to cruise  (seconds)
    
    
    cout << "Welcome to the windbag emporium." << endl;
    cout << "You'll rise up, cruise a while, then descend." << endl;
    cout << "How high (in meters) do you want to rise: ";
    cin >> rise;

    cout << "How long (in seconds) do you want to cruise: ";
    cin >> duration;
    
    montgolfier.Ascend(rise);       // ascend to specified height
    montgolfier.Cruise(duration);   // cruise for specified time-steps
    montgolfier.Descend(0);         // come to earth
    
    return 0;
}