Chapter 41

Several days later, the Thermos Flask was completed.

The only materials were Glass, mercury, a wooden stopper, and an outer casing. Though it looked simple, there had been quite a few difficulties at the start of firing it.

But once there was a first, there would be a second.

The kiln workers had gained experience, and their skills would only grow more refined.

Once the Thermos Flask came into being, Cheng Hao tested it first. He poured boiling water into the flask, plugged it tightly with the wooden stopper, left it for a full day and night, then poured the water out again.

The water in the cup was warm to the touch.

"Eldest Brother," Cheng Hao said excitedly, slapping his shoulder hard, "it really keeps heat in!"

Qin Ke's expression remained blank. He raised a hand and brushed away Cheng Hao's thick arm, shot him a cold glance, then asked Rong Xi, "Are you all right?"

Cheng did not know his own strength. How could Lanzhi withstand that?

Before Rong Xi could reply, Cheng Hao, failing to grasp his meaning, asked, "Could it be that Eldest Brother has an injury on his shoulder? Then it truly was my fault!"

"Uncle Cheng, my shoulder is uninjured." Rong Xi helplessly changed the subject. "The workshop will be completed in a few days. How does Uncle Cheng plan to assign the craftsmen then?"

The Military Equipment Bureau, as its name suggested, was where military weapons were made. This was a court secret and could not easily be revealed to outsiders.

The chosen craftsmen had to be trustworthy.

"Eldest Brother, rest assured. The Prince and I have long had a plan for this matter. We certainly will not allow petty scoundrels to make trouble," Cheng Hao replied solemnly.

Rong Xi nodded. "In that