Will I ever run out of vintage science fiction stories about invisibility to write about? I hope so, because otherwise my book draft will never be polished off.

Some authors of weird fiction seem to be addicted to invisibility. One notable example is H.P. Lovecraft, who published The Dunwich Horror in 1929 and In the Walls of Eryx in 1936, together with Kenneth Sterling. The former story is about an invisible monster that is released upon the unsuspecting town of Dunwich, and the latter is a science fiction story about an invisible maze on the planet Venus and the prospector who gets trapped within it due to his greed.

Another notable example of an invisibility addict is Victor Rousseau. Only days ago I wrote about his 1916 novel The Sea Demons, about a race of invisible aquatic humanoids who plan to rise up and conquer the surface world. Yesterday, I came across another of his tales: The Invisible Death, published in the October 1930 issue of Astounding Stories of Super-Science.

So let’s take a look at the very, extremely silly story of The Invisible Death, and talk a little about the “science” described within!

The Invisible Death might best be called a “science thriller. Through the character of Captain Richard Rennell, it tells the story of the United States government fighting against an invisible army that seeks to subjugate the entire country!

The tale begins on Death Row. A prisoner named Von Kettler has been sentenced to death for murder; he was caught in the act of stealing government documents and shot dead the security guard who tried to stop him. Law enforcement knows that Kettler is part of some sort of conspiracy to overthrow the governments of the world, and offers him his life in exchange for more details. Kettler laughs off the deal, and declares that he will walk right out of his cell and the prison entirely before his death, with everyone powerless to stop him! Everyone assumes that he is mad, but at the time of his arranged execution, his cell is found empty.

Dick Rennell is put on the case, not only to find Kettler, but to organize the hunt for the members of the so-called Invisible Empire and its leader, known as the Invisible Emperor. But he hardly starts his investigation when the Empire attacks, abducting the President of the United States right from the White House! One conspirator is killed during the attack, and they are found to be entirely invisible, thanks to special garments that they wear:

The garment taken from the slain soldier had been examined by a half-dozen of the leading chemists of the East. Pending the arrival from New York of the celebrated Professor Hosmeyer, it was deposited under military guard in a dark closet. The result was unfortunate. The garment exhibited to the assembled scientists was a mere bifurcated silken bag.

The gas with which it had been impregnated, though it had been heavy enough to adhere to the fabric for hours, had also been volatile enough to have disappeared completely, leaving a residue which was identified as a magnesium isotope.

The situation deteriorates quickly. Von Kettler is sent as an ambassador from the Invisible Empire, and their demand is nothing less than the complete surrender and subjugation of the United States to the Invisible Emperor. This deal is naturally rejected, and the Empire wastes no time in bombing Washington, D.C. using invisible bombers. They expand outward from there, leaving a path of destruction across the entire country. It is up to Rennell, and a brilliant scientist named Luke Evans, to find a way to track down and defeat the forces of the Invisible Emperor before it is too late.

The invisibility of the story is of the “perfect absorption” type, as Evans, the inventor of the invisibility gas, explains:

Luke Evans placed the square black case upon the table. “It’s simple, like all big things, sir,” he answered. “The original shadow-breaking device that I invented was a heavy, inert gas, invisible, but almost as viscous as paint. Applied to textiles, to inorganic matter, to animal bodies, it adheres for hours. Its property is to render such substances invisible by absorbing all the visible light rays that fall upon it, from red to violet. Light passes through all substances that are coated with this paint as if they did not exist.”

The idea, is seems, is that the viscous invisibility substance absorbs all light illuminating a target object; since we see objects using the light reflected from them, this makes the object impossible to see. But this explanation is completely at odds with the last sentence of the above passage: “Light passes through all substances that are coated with this paint as if they did not exist.” If the object is highly absorptive, then that is the opposite of light actually passing through it! It seems that Rousseau did not have a particularly clear understanding of the optics involved — or he just didn’t worry about it.

Luke Evans introduces an “antidote” to the invisibility: a beam of darkness, that makes the invisible objects glow!

How does this darkness work? Rousseau, through Evans, tries to explain.

“But how does this darkness make the invisible airships luminous?” asked Stopford. “Why does not your darkness destroy all light?”

“In this way, sir,” replied the old inventor. “The shadow-breaking gas with which the airships are painted confers invisibility because it absorbs sunlight. But it does not absorb the still more rapid waves, or oscillations which manifest themselves as radio-activity. On the contrary, it gathers and reflects these.

“Now Roentgen, the discoverer of the X-ray, observed that if X-rays are allowed to enter the eye of an observer who is in complete darkness, the retina receives a stimulus, and light is perceived, due to the fluorescent action of the X-rays upon the eyeball.

“Consequently, by creating a beam of complete darkness, I bring into clear visibility the fluorescent gas that coats the airships; in other words, the airships become visible.”

There’s a lot to unpack here. First, it seems like Rousseau was roughly inspired by the use of blacklight (ultraviolet light) to make certain objects glow. It really sounds like Rousseau read half of an article about ultraviolet light, skipped the rest, forgot half of it, and wrote his story based on the little remembered. But it is an interesting idea, and one that is a challenge and limitation for modern researchers that have pondered the creation of invisibility cloaks: you can make a cloak potentially invisible for one wavelength of light, or multiple wavelengths, but certainly not for all wavelengths.

Rousseau also mentions Roentgen, the discoverer of X-rays. Ever since their discovery, X-rays have been associated with invisibility; if X-rays can make a person see-through, the (flawed) reasoning goes, then why couldn’t they make other things invisible? H.G. Wells took advantage of this association in his classic 1897 book The Invisible Man, and X-rays and invisibility have been entwined ever since. Rousseau actually uses another property of the invisible X-rays, their ability to still stimulate the retina of the eye, in his explanation, but it’s apparent to me that he is using their association with invisibility in his favor.

Invisibility isn’t the only trick the Invisible Empire has up its sleeve. Once the government finds the base of the Empire, they immediately launch an airstrike. But flying over the island lair, Rennell and his fellow pilots find their planes frozen in place!

Dick fired two Very lights as a signal to his flight to scatter. What were they doing, bunching together like a flock of sheep, when at any moment the enemy planes might come swooping in, riddling them with bullets? He thrust the stick forward—and then realized that his controls had gone dead!

He thought for a moment that a wire had snapped. But the stick responded perfectly to his hand, only it had no longer control over his plane. He kicked right rudder, and the plane remained motionless. He pushed home the soaring lever, to neutralize the helicopter and the plane still soared.

Then he noticed that the needle of his earth-inductor compass-indicator was oscillating madly, and realized that it was not his plane that was at fault.

Underneath him, his flight seemed to be milling wildly as the ships turned in every direction of the compass. But not for long. They were nosing in, until the whole flight resembled an enormous airplane engine, with twelve radial points, corresponding to their propellers, and the noses pointing symmetrically inward, like a herd of game, yarding in winter time.

And now the true significance came home to Dick. A vertical line of magnetic force, an invisible mast, had been shot upward from the ground. The airplanes were moored to it by their noses, as effectively as if they had been fastened with steel wires.

And he, too, was struggling against that magnetic force that was slowly drawing him, despite his utmost efforts, to a fixed position five hundred feet above his flight.

This “vertical line of magnetic force” is another example of how silly The Invisible Death is! Rousseau uses a lot of magical technology to create twists and turns in the story, though to a modern reader they seem more contrived than exciting. The Invisible Death doesn’t have quite the same spark of imagination that Rousseau’s earlier The Sea Demons possessed.

In fact, even the title is not original. The January 1930 issue of Astounding Stories of Super-Science — the same magazine that Rousseau’s story would appear in several months later — included a story called “Invisible Death,” by Anthony Pelcher. It seems clear that Rousseau was aware of this story, because one of Rousseau’s own stories appeared in the very same issue! Pelcher’s tale is next on my reading list; I’m curious to see if Rousseau adopted any other aspects of the tale.

So I don’t consider The Invisible Death to be a particularly stellar example of an invisibility story, but it was fun to see yet another take on the subgenre of science fiction!