Storms, Lightning, and All the Other Fires that Ignite in the Air

Finally, lightning can sometimes be converted into a very hard stone, which breaks and shatters everything it encounters, if among these very penetrating exhalations there are a quantity of these others that are greasy and sulfurous especially if there are also coarser ones, similar to this earth that is found at the bottom of rainwater when it is allowed to settle in some vessel.

Having mixed certain portions of this earth, nitrate, and sulfur, if the fire is put in this composition, a stone is suddenly formed.

If the cloud opens by the side, as towards G, the lightning being launched sideways, meets the tips of towers or rocks rather than low places, as we see towards H. But even when the cloud breaks from below, there is a reason why lightning falls more on high and eminent places than on others. For if, for example, the cloud B is not more disposed to break in one place than in another, it is certain that it will have to break in the one marked F, because of the resistance of the bell tower that is below.

There is also a reason why each clap of thunder is usually followed by a shower of rain, and why when this rain comes very abundantly, it does not thunder much more.

For if the force, with which the upper cloud shakes the lower one by falling on it, is great enough to make it all descend, it is evident that the thunder must cease.

If it is less, it does not fail to often make several snowflakes fall out of it, which melting in the air make rain.

People believe that loud noise, such as bells, or cannons, can reduce the effect of lightning because it helps to dissipate and make the lower cloud fall, by shaking the snow of which it is composed.

As those who are accustomed to traveling in valleys where avalanches are to be feared know enough.

They even refrain from speaking and coughing when passing there, for fear that the sound of their voice will stir the snow.

But it sometimes lightens without thundering, so in places in the air where there are many exhalations and few vapors, clouds can be formed so thin and light that falling from high enough one on the other they do not hear any thunder, nor excite any storm in the air, notwithstanding that they wrap and join together several exhalations; from which they compose not only these lesser flames which one would say to be stars falling from the sky, or others which traverse it, but also rather large fireballs, which reaching us are like diminutives of lightning.

Even since there are exhalations of several different natures, I do not think it is impossible that the clouds, by pressing them, sometimes compose a material, which according to the color and consistency it will have, seems like milk, or blood, or meat; or else which by burning becomes such that it is taken for iron, or stones; or finally which by corrupting generates some small animals in a short time.

As we often read among the prodigies that it has rained iron, or blood, or grasshoppers, or similar things.

Without any clouds, the exhalations can be heaped up and ignited by the sole breath of the winds, especially when there are two or more contrary ones that meet.

Without winds and clouds, a subtle and penetrating exhalation made up of salts can insinuate itself into the pores of another which is greasy and sulfurous. This can produce light flames both at the top and bottom of the air, as we see at the top these stars which traverse it.

At the bottom both these burning or will-o’-the-wisps which play there, and these others which stop on certain bodies, such as the hair of children, or the mane of horses, or the tips of pikes which have been rubbed with oil to clean them, or similar things.

They can be ignited by:

• a violent agitation
• often the mere mixture of two different bodies

We see this when we:

• pour water on lime
• enclose hay before it is dry
• and so on.

But all these fires have very little force compared to lightning.

This is because they are composed only of the softest and stickiest parts of the oils; notwithstanding that the liveliest and most penetrating salts also ordinarily concur to produce them.

For these do not stop for that among the others, but promptly spread out in the open air after they have ignited them. Instead of which lightning is mainly composed of these liveliest and most penetrating ones, which being very violently pressed and driven by the clouds, carry the others with them to the ground. And those who know how much force and speed the fire of saltpeter and sulfur mixed together has, instead of the greasy part of sulfur being separated from its spirits would have very little; will not find anything doubtful in this.

For the duration of the fires that stop or flutter around us, it can be more or less long, according to whether their flame is more or less slow, and their material more or less thick and tight: But for that of the fires which are only seen at the top of the air, it cannot be but very short, because if their material were not very rare, their weight would make them descend.

I find that the Philosophers were right to compare them to this flame, which we see running all the way along the smoke, which comes out of a torch that has just been extinguished, when being approached by another torch it ignites. But I am very astonished that after that they could have imagined that the Comets, and the columns or beams of fire, which are sometimes seen in the sky, were composed of exhalations, for they last incomparably longer.

And because I have endeavored to curiously explain their production and their nature in another treatise, and that I do not believe that they belong to meteors, any more than earthquakes, and minerals, that many writers heap together there, I will only speak here of certain lights, which appearing at night during a calm and serene time, give idle people the subject of imagining squadrons of phantoms fighting in the air, and to whom they presage the loss or victory of the party they favor, according to whether fear or hope predominates in their fancy.

Even because I have never seen such sights, and I know how the reports of them are usually falsified and augmented by superstition and ignorance, I will be content to touch in a few words all the causes that seem to me capable of producing them.

1. There are several clouds in the air, small enough to be taken for so many soldiers.

These fall one on the other, envelop enough exhalations to cause a quantity of small flashes, and throw small fires and maybe also make small noises, by which means these soldiers seem to fight.

2. There are clouds that, instead of falling one on the other, receive their light from the fires and flashes of some great storm which takes place elsewhere so far away that it cannot be perceived there.

3. These clouds, or some other more northern ones from which they receive their light, are so high that the sun’s rays reach them.

For if we take heed to the Refractions and Reflections that two or three such clouds can cause, we will find that they do not need to be very high to make such lights appear towards the North, after the hour of twilight has passed; and sometimes also the sun itself, at the time it should be set.

But this does not seem to belong so much to this discourse as to the following ones, where I have the intention of speaking of all the things that can be seen in the air without being there; after having here finished the explanation of all those that are seen there, in the same way that they are there.