The sun is shining and the warm breeze is light. The street under the linden tree is full of traffic, the commercial port is continuous, and the magnificent and towering buildings rise from the ground, towering clouds, reflecting the dazzling light under the morning glow.

The nameplate of the Airship Flight Propulsion Association hangs in mid-air, and it is also very conspicuous in the street under the linden tree that is covered with advertising posters.

It didn't take long for McClan to see where it was. The elevator went straight up, the iron door opened and closed, and when he stepped out of the elevator, he looked at the long office corridor full of large and small offices.

After a few minutes, McClan finally found a purple wood door with the word "zeppelin" written on it. McLaan adjusted his breathing, raised his hand and tapped lightly on the door a few times, and when he heard a syllable from inside, he pushed the door open with his hand.

Sofa coffee table, chair square table. Two bronze incense burners exude a faint fragrance in the corner, and the simple furniture decoration adds a touch of natural elegance to the whole office.

On the chair behind the square table, a typical German-style old man with a hooked nose was writing something on the table. When he saw McClan standing in the doorway, there was obviously a slight astonishment and stunned on his gray-yellow face. I didn't seem to expect that someone who wasn't a waiter would appear in front of me.

He put down the carved quill in his hand and asked politely: "I am Ferdinand von Zeppelin, may I ask this gentleman who are you looking for?" ”

Zeppelin's voice was condensed and deep, without the weakness and trembling in the tone of an ordinary old man.

Even though he is nearly seventy years old, he is still ruddy and full of energy. Hearing Zeppelin's self-report, McLaen's face finally bloomed with a happy smile, and he said, "Mr. Zeppelin, the purpose of my visit this time is to appreciate Your Excellency's research on airships. Oh yes, I almost forgot to introduce myself, my name is Etel Mackellen, an Italian, and I've been known for your deeds for a long time. ”

Zeppelin was born in 1838 into an aristocratic family in the Grand Duchy of Baden, where his father was the chief of the Imperial Court of the Grand Duchy of Baden. Zeppelin developed a keen interest in construction machinery from an early age, and this impulse to work from the roots was directly related to his later brilliant achievements.

Beginning in 1887, the retired Zeppelin was fully engaged in the improvement of airship technology.

As an important carrier to realize the dream of human aviation, airships were born for more than 100 years at that time. However, the airships put into use at that time were all soft airships, which carried pods with hydrogen-filled airbags as suspension devices, and their disadvantage was that the load capacity was small, and it was difficult to meet diverse needs.

In order to improve the overall performance of the airship as a whole, and then open up a broader space for the development of the airship industry, Zeppelin decided to open up a new way.

On the basis of the existing research results at that time, he creatively proposed the design scheme of the rigid airship. Specifically, a frame is made of aluminum, and then multiple compartments are isolated in the frame, and corresponding airbags are placed in each compartment. When everything is ready, the hull skin is covered on the outside of the hull, so that the suspension device of the rigid airship is created.

Although the idea was good, it was difficult to operate in practice, because of the weight, lift, and structure, so Zeppelin faced many reasons. Of course, there is a more important reason, and that is the problem of funding, compared with the petite aircraft, the development of airships requires much higher funds. Not to mention that Zeppelin is still developing a hard airship.

Take the first hard airship he developed, "LZ No. 1", for example, there are 17 airbags in the hull, with a total volume of 12,000 cubic meters, which is 5 to 6 times larger than the soft airship at that time. The cost of this "LZ 1-1" is as high as 1.8 million marks, and if he had not found more than a dozen like-minded people, this money would have drained his savings.

In the spring of 1897, Duilio and Siegel, two Italians, carried out the first mechanical flight of mankind, which made more people enthusiastic about flying.

Of course, this has led to a lot fewer people willing to invest in the research of airships, which are slow and difficult to operate.

And after hearing that someone had come all the way to visit him for the airship, this Zeppelin was also interested. "I don't know what Mr. McLalen has about airships, we can discuss it."

"I can't say enough, but I think the future prospects for airships are very good, and at the moment, airships have a lot of potential in terms of payload and airworthiness, which can make airships a great aircraft for air transportation. For example, an airship can carry thirty or fifty people from Berlin all the way to London, which may only take a day. ”

Mackellen's remarks about airships convinced Zeppelin that he was indeed the one who had studied airships.

However, the visitor then changed his mind and continued. "But I think there are a couple of problems that need to be solved at the moment, the first of which is the danger. The airship currently uses hydrogen as the gas in the airbag, and hydrogen is too dangerous, and it only takes a spark to make an expensive airship come to naught, which is not conducive to the promotion of airships at all. ”

McLaen made Zeppelin frown, because the problem was so difficult to solve. At present, airship researchers in various countries use hydrogen, and everyone knows the dangers of hydrogen, but hydrogen is cheap. That's right, these airship researchers have limited funds and can do nothing without hydrogen.

"I agree with your Excellency, but at the moment hydrogen filling is also a last resort. Aluminum is not cheap, and if you use expensive gases that are not dangerous, then the construction of this airship will be so amazing that few people can afford it. ”

Yes, for Zeppelin, he doesn't know the dangers of hydrogen, but with so much money, let's ensure the success of research and development first.

And in the face of Zeppelin's words, McLaen immediately replied. "Mr. Zeppelin, I'm actually here to support Your Excellency, but I want the airship to be used for research on helium."

Helium?

Zeppelin, of course, didn't know about the gas, but McLaen introduced it immediately.

Helium is a colorless and odorless inert gas, which is chemically inactive and difficult to react with other substances in a normal state.

And helium was discovered very late, and it was not until 1895 that the British chemist Sir William Ramsay discovered that there was helium on Earth in a radioactive vein rich in uranium. And last year, Italian oil companies discovered large quantities of helium in Libyan gas fields.

Of course, the more important thing is that helium is very light, only 0.1786 kg/m3, which is a bit heavier than 0.089 kg/m3 hydrogen. But in terms of security, the two are not the same.

After listening to Mackellen's account, Zeppelin fell into deep thought.

"I wonder how much money Your Excellency is willing to fund?"

In the face of Zeppelin's inquiry, McLaen immediately gestured five fingers. "Five million marks, but helium."

"Deal."

After a brief handshake between the two, Zeppelin spoke. "Mr. McLene, I don't know where Your Excellency is?"

As an experienced person, Zeppelin saw at a glance that the McLaan in front of him did not look like a person who could take charge of things, but since he dared to give 500 marks, he must have relied on it, so he needed to ask.

In the face of Zeppelin's inquiry, McLaen smiled and showed his snow-white teeth. "I currently work at the Savoy Royal Investment Fund."