The third part of John McPhee’s The Control of Nature concerned the San Gabriel Mountains east of Los Angeles. I had a difficult time identifying them on maps and aerial photographs, so this review will not be illustrated. See part 1 of this review here, and part two here.

Somewhere close to L.A., this mountain range is unusual in that it is growing, not eroding. Tectonic forces are pushing the mountains higher. Yet, the mountains are eroding in a sense in that they are sloughing off rock. In any given heavy rainfall, rocks and mud flow down from the mountains. No big deal, you say…except the growth of Los Angeles has caused subdivisions to be built up onto the mountains, right up to the point where the land gets too steep to build on. These subdivisions are what the sloughing rock and mud encounter first.

McPhee does a good job of explaining the terror that residents had when first the noise, then the detritus, hits their property. The flow goes into yards and through houses, or sometimes moves houses, and tears up and blocks streets.

To protect residences, various governmental agencies, such as regional flood control districts, have been formed to construct and maintain catchment areas upstream of the houses. I have a difficult time envisioning this. Since the rockslides could come anywhere on the mountains, and since predicting the quantity of “rock flow” would be less of a science than predicting runoff from rainfall, for this to be effective, you would need a huge catchment basin across the entire face of the mountain range. It sounds physically impossible and financially impractical.

Yet, it is being done (as of 1989, the time the book was written, that is). Sometimes the catchments are successful, sometimes not. But officials and residents labor on, doing whatever can be done to anticipate from whence the rock will come, and catching it before it hits houses—to control nature.

In this section, as in the two previous ones, McPhee tells a compelling story, but tells it too long. Too many stories. Too many names of victims and officials. Too many occasions for the reader to zone out, as I did all too frequently. The 272 page book would have been just as informative and more compelling if it had been told in 200 pages, in my engineering opinion.

Now, the big questions: a rating and a disposition. The latter is easy. This book is not a keeper. I read it in anticipation of putting it on the donation/sale stack, and there it goes after I post this. As to a rating, I think only 3-stars, and those two stars marked off because of the length. Would a non-engineer be able to read it and glean information from and be entertained by it? Yes, absolutely, maybe even more than I was. This is a book I’m quite glad I read, but could never see myself reading again.

In my last post, I began a review of the book The Control of Nature by John McPhee. I mentioned that the book had three parts, and that I would be doing a review in three parts. See the first part of the review here.

The second part is titled “Cooling the Lava”. This concerns a volcanic eruption in Iceland in February 1973. It’s now been over a month since I read this section (maybe closer to two months), and I don’t remember all the names involved. Basically, this was on an island named Vestmannaeyar on the south side of Iceland. It included a sizable town, an important port, and a valuable fishing fleet and the infrastructure to support this. The town was Heimaey. The volcano was a new one, coming up from nothing but the hot works below the nation’s surface. See the photo I clipped from Google Earth.

Almost from the minute the volcano appeared, the fire boats, engines, hoses, and water came out and people directed it onto the flowing lava. People in the country laughed at them. But as the lava increased, so did the hoses and water. The laughter faded away and fear came.

Many people fled Heimaey. Others came and joined the fire brigade. Slowly, the hose holders won the battle. The lava hardened at the surface and new lava, when it came, piled up higher and higher, but ceased to move forward. The harbor was saved. In fact, the harbor entrance width was cut in half, reducing wave intrusion from the sea but leaving plenty of space for ships and boats to get in and out.

McPhee does a good job of explaining what was done, how the lava behaved, and the aftermath. I especially enjoyed the later. The surface cooled enough to walk on, but stick a thermometer through the surface, and a few inches down you have temperatures that will boil water. The crust, though hard enough to walk on, is thin. This is true even years after the eruption.

My main complaint about this section of the book is the same as the first section: it was too long. McPhee went on and on. He shifted from Iceland to Hawaii, where they took the opposite tack from Iceland. They let the lava flow and hoped for the best. It was interesting to learn about the difference in approaches, but it really dragged out this section. Actually, the Hawaii part wasn’t too long. It was the Iceland portion. I don’t know what I would cut out, but something really needed to be cut.

This makes two parts of the book with the same opinion on quality. Stay tuned for the third part, and my overall conclusion. I’m not sure whether that will be on Monday, or perhaps later.