After arranging for the troops to camp, Guan Gong sent a large number of small ships to the front to reconnoitre, and in addition, several medium-sized warships were responsible for towing powered hot air balloons.

The power hot air balloon is different from the previous use of a foot-operated propeller as the power source, and the "hot air engine" is added as the power source. This so-called "hot gas engine" is actually the Stirling engine. In the past, some "hot air engines" were put on hot air balloons for trial, but they were not mature products, and now the technology has basically matured.

The Stirling engine is powered by cooling, compression, heat absorption, expansion ~ expansion of the working medium (gas) in the cylinder for a cycle of power, which is an external combustion engine, simple in structure and very small in size, which is very suitable for use in hot air balloons.

Over the years, the institute has been committed to the research of engines. The steam engine is not yet mature, but the structure of the much simpler "hot gas engine" has achieved good results, although the problem of sealing still can not be perfectly solved, so that the trial life is shortened, but it can finally be used for practicality.

The cylinder of this "hot gas engine" has a big ~ thick leg, which looks like a giant test tube, connected by a guide rail, and controls the cylinder to slide in and out of the furnace through a handle. By controlling the depth of the cylinder into the furnace, the "infinitely variable speed" of the hot air balloon can be realized. The more parts of the cylinder enter the furnace, the more heat it gets, the higher the power output, and correspondingly, the faster the propeller speed.

The whole cylinder is completely slid into the stove and roasted, which is when the power is at its highest, that is, when the hot air balloon flies the fastest. When the cylinder is completely out of the furnace, the cylinder cannot contact the heat source and the power output is zero.

In this era, there was no speed shifting device, and the masters of the mechanism cleverly solved the problem of changing the speed of hot air balloons through this method. Of course, such a shifter is very sluggish, because it takes a long time for the cylinders to heat up and cool down, so the speed of the propellers changes very slowly.

In order to deal with the emergency, the masters of the mechanism set up a braking device, which can quickly brake the propeller, but the problem of slow acceleration cannot be solved for the time being, this problem belongs to the inherent defect of this engine, belongs to the technical generation, and it takes a long time to study to solve, and it is likely that it will not be solved even before the internal combustion engine comes out.

Because this "hot air engine" takes up some of the heat energy, the new hot air balloon has to make the stove a little bigger to provide enough heat. Correspondingly, the basket of the hot air balloon will also be larger, and the balloon will also be much larger than the original hot air balloon.

So, the whole volume of this new hot air balloon is a lot bigger, it can carry a lot more weight, it can carry more fuel and more passengers. At its limit, with only one hour of fuel to sustain the flight, the new balloon can carry up to ten people.

In this way, whether it is reconnaissance, airborne or air raid, it is much more convenient, more fuel means higher flight and more endurance, and large loading capacity means that this can be loaded with more bombs or airborne troops. However, at this time, the main task of these hot air balloons is reconnaissance.

Although this kind of hot air balloon claims to have a power device, it can only move freely to a certain extent, and those airships in later generations cannot be compared at all, if the wind is particularly strong, it will be very troublesome, and if you want to fight against nature, it is not enough to see with such a little power. Therefore, this modified version of the hot air balloon is still tied to a horse-drawn carriage or boat for most of the time.

If you really need to move freely off the tether, you must measure the wind direction and speed before moving, and when the wind speed exceeds a certain level, it is not allowed to move. The current hot air balloon is to reconnoiter the river and the attached lake, and the range of activity is relatively small, and there is no need for free movement at all, so each hot air balloon is tied to a medium-sized warship with a rope, and then dispersed to all directions to reconnoiter under the protection of other frigates.

The hot air balloon flew high, and with the help of high-powered telescopes, the range of dozens of miles on both sides of the Yangtze River could be seen clearly, all the ships and personnel had nothing to hide, and the entire battlefield situation was once again one-way transparent to the Han army. Not to mention, more than a day later, the enemy situation was really discovered by the reconnaissance hot air balloon.

The scouts on the hot air balloon found that in the section of the river near Jiangxia, there was a Jiangxin Island, and there were many Wu troops hidden on the island. Further reconnaissance found that the terrain on both sides of the Yangtze River here is extremely complicated, there is more than one tributary on both banks, and some places have expanded into lakes, and there are large areas of reeds, lotus, water chestnuts and other aquatic plants on the surface of the lake.

Crucially, the scouts discovered that many of the tributaries on both sides of the river were hiding a wide variety of boats, and they were huge in number. Soon, a military map with reconnaissance information appeared in the bridge of the flagship, and Guan Gong, Wang Fu, Zhuge Wang, and other cadres of the Jingzhou Navy surrounded this map and began to carry out military discussions.

"I reckon that the enemy will stop us at this position." It was Zhuge Wang who spoke, holding a slender bamboo in his hand, pointing to a location on the map and talking. This location is not far in front of the island in the middle of the river.

"Although I do not yet know what means he will use to halt such a large fleet of ours, judging by the forces they are lying in ambush around us, this is the most suitable position to attack us. Maybe they will put up some obstacles on the river, maybe it has something to do with this island (Jiangxin Island). ”

Everyone nodded again and again when they heard Zhuge Wang's explanation, and felt that his analysis was very reasonable. Only to hear Zhuge Wang continue: "If they successfully intercept our fleet here, it is very likely that they will start the first wave of attack from this reed swing on the north shore. ”

Zhuge Wang circled the bamboo in his hand and said to a lake-like location on the map, "This reed swing area is dozens of hectares, enough to hide a large number of people and horses." And closest to where our fleet could stop, the best position to launch the first battle. Although the scouts found no signs of human activity here, I reckon there was probably no sign of the enemy because the tall reeds blocked the view.

Enemy troop was found in almost all nearby tributaries and lakes, and there was no reason why there were no ambushes in this excellent location. If the people of Eastern Wu really didn't ambush the ships here, then the commander of Eastern Wu would definitely be a big fool~. ”

"Hahaha" Hearing this, everyone couldn't help but laugh.

"I guess the ambush here is all boats. The boat is low, and it is normal to hide in the reeds and not see people at all. In addition, these boats must be speedboats, the fastest kind, which can quickly rush in front of the enemy to carry out strikes. As for the means of attack, you might as well guess it, in my opinion, it is very likely that they will attack with fire. It is quite possible that quite a few of the ships in ambush here are fireships, or even fire-breathers. ”

Although Zhuge Wang said that people could guess, he didn't give others a chance to speak at all, and kept talking about the answers he had guessed in his heart.