---
title: "Dream Pool Essays"
chunk: 3/5
source: "https://en.wikipedia.org/wiki/Dream_Pool_Essays"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:31:47.882363+00:00"
instance: "kb-cron"
---

=== Personal beliefs and philosophy ===
Of Taoism and the inability of empirical science to explain everything in the world, Shen Kuo wrote:

Those in the world who speak of the regularities underlying the phenomena, it seems, manage to apprehend their crude traces. But these regularities have their very subtle aspect, which those who rely on mathematical astronomy cannot know of. Still even these are nothing more than traces. As for the spiritual processes described in the [Book of Changes] that "when they are stimulated, penetrate every situation in the realm," mere traces have nothing to do with them. This spiritual state by which foreknowledge is attained can hardly be sought through changes, of which in any case only the cruder sort are attainable. What I have called the subtlest aspect of these traces, those who discuss the celestial bodies attempt to know by depending on mathematical astronomy; but astronomy is nothing more than the outcome of conjecture.

=== Dissertation on the Timberwork Manual ===
Below are two passages from Shen's book outlining the basics contained in Yu Hao's Timberwork Manual. Yu Hao was a Chinese architect of the earlier 10th, and Kuo was one to praise his work. In the first quote, Shen Kuo describes a scene where Yu Hao gives advice to another artisan architect about slanting struts for diagonal wind bracing:

When Mr. Qian (Wei-yan) was Governor of the two Zhejiang provinces, he authorized the building of a wooden pagoda at the Fan-tian Si (Brahma-Heaven Temple) in Hangzhou with a design of twice three stories. While it was under construction General Chhien went up to the top and was worried because it swayed a little. But the Master-Builder explained that as the tiles had not yet been put on, the upper part was still rather light, hence the effect. So then they put on all the tiles, but the sway continued as before. Being at a loss what to do, he privately sent his wife to see the wife of Yu Hao with a present of golden hair pins, and enquire about the cause of the motion. (Yu) Hao laughed and said: 'That's easy, just fit in struts (pan) to settle the work, fixed with (iron) nails, and it will not move any more.' The Master-Builder followed his advice, and the tower stood quite firm. This is because the nailed struts filled in and bound together (all the members) up and down so that the six planes (above and below, front and back, left and right) were mutually linked like the cage of the thorax. Although people might walk on the struts, the six planes grasped and supported each other, so naturally there could be no more motion. Everybody acknowledged the expertise thus shown.

In this next quote, Shen Kuo describes the dimensions and types of architecture outlined in Yu Hao's book:

Methods of building construction are described in the Timberwork Manual, which, some say, was written by Yu Hao. (According to that book), buildings have three basic units of proportion, what is above the cross-beams follows the Upperwork Unit, what is above the ground floor follows the Middlework Unit, and everything below that (platforms, foundations, paving, etc.) follows the Lowerwork Unit. The length of the cross-beams will naturally govern the lengths of the uppermost cross-beams as well as the rafters, etc. Thus for a (main) cross-beam of (8 ft) length, an uppermost cross-beam of (3.5 ft) length will be needed. (The proportions are maintained) in larger and smaller halls. This (2/28) is the Upperwork Unit. Similarly, the dimensions of the foundations must match the dimensions of the columns to be used, as also those of the (side-) rafters, etc. For example, a column (11 ft) high will need a platform (4.5 ft) high. So also for all the other components, corbelled brackets, projecting rafters, other rafters, all have their fixed proportions. All these follow the Middlework Unit (2/24). Now below of ramps (and steps) there are three kinds, steep, easy-going, and intermediate. In places these gradients are based upon a unit derived from the imperial litters. Steep ramps are ramps for ascending which the leading and trailing bearers have to extend their arms fully down and up respectively (ratio 3/35). Easy-going ramps are those for which the leaders use elbow length and the trailers shoulder height (ratio 1/38); intermediate ones are negotiated by the leaders with downstretched arms and trailers at shoulder height (ratio 2/18). These are the Lowerwork Units. The book (of Yu Hao) had three chapters. But builders in recent years have become much more precise and skillful (yen shan) than formerly. Thus for some time past the old Timberwork Manual has fallen out of use. But (unfortunately) there is hardly anybody capable of writing a new one. To do that would be a masterpiece in itself!

=== Botany and zoology ===
Shen Kuo described the natural predator insect similarly shaped to the gou-he ("dog-grubs") which preyed upon the agricultural pest infestation of zi-fang, the moth Leucania separata:

In the Yuan-Feng reign period (1078–1085), in the Qingzhou region, an outbreak of zi-fang insects caused serious damage to the crops in the fields in autumn. Suddenly another insect appeared in swarms of thousands and tens of thousands, covering the entire ground area. It was shaped like earth-burrowing gou-he (dog grubs), and its mouth was flanked by pincers. Whenever it met a zi-fang, it would seize it with the pincers and break the poor beast into two bits. Within ten days all the zi-fang had disappeared, so the locality had an abundant harvest. Such kinds of insects have been known since antiquity and the local people call them pang-bu-ken ("not allowing other [insects] to be").

=== Natural phenomena ===
Around 1078, Shen Kuo wrote an accurate description of the damaging effects of lightning to buildings and to the specific materials of objects within. Taking an objective and speculative viewpoint, he stated: