That time I tried to blow an egg

It was bound to happen sooner or later. Do enough reading on a subject and sooner or later you start to wonder what it would be like to have a go (this is also, coincidentally, why I'd like to have a go at breeding dragonflies). Unfortunately I lack the specialised tools to make a proper job of egg-blowing, the drills and pipes of the collectors' heyday were relatively precise instruments and while there are plenty still around, I don't think anyone would appreciate me absconding with them. With that in mind, I had to improvise.



The scattershot approach

To a collector, the final appearance of the egg was paramount, so they generally made every attempt to choose a bland spot to drill without any interesting marking. During the project I saw one or two with holes on an end, but almost all are somewhere on the sides of the egg. I didn't find any sources explaining why drilling at the points was uncommon, but I suspect it is due to the robust shape of most eggs.

For my own effort, none of the eggs were particularly special to look at, so I selected an arbitrary point on the side. Unfortunately my initial attempt didn't work so well. Chemically speaking eggshells are quite rigid; while strong, they tend to shatter and avoiding that is quite tricky. None of the tools on that penknife were suitably deft.

The subtle approach

Counterintuitive it may be, but the serrations on this knife were very handy for scoring a mark for the "drilling." I don't know if scoring the shell was standard practice among the collectors of old, certainly none of the contemporary guides I read mentioned it. That said, some of the eggs in The Hunterian bear some scratches around the drill hole (exit hole? Blowhole?) which would fit the pattern. I marked an X and started twisting the point of the knife in to make an indent.

Oops

Ok, that didn't work so well. Those useful serrations got caught in the shell as I drilled deeper and levered a chunk of it off. Oh well, if at first you don't succeed...

Destroy all evidence that you tried

I tried a number of tools this time, in the process educating myself about the relative toughness of the contents of my flat. Cocktail sticks were too soft, drawing pins too narrow, knives too flat... it was a fun time. Having made the scoring point with the knife, I finally found a winner when I tried a metal skewer.

How did I hold the camera?

Of course I could only get away with using such clunking great tools because chicken eggs are rather large and tough, at least compared to many other kinds. Smaller eggs, like robins' for example, are a great deal thinner and more delicate. Michael Prynne, mentioned in the previous post, claimed to keep a large darning needle on him at all times, just in case he espied a worthy addition to his collection.

During the course of my research, most sources suggested that the one-hole method was relatively new, replacing an older two-hole method from the early 19th century onwards. The two-hole method is fairly obvious, you blow in one hole and the contents are ejected through the other. Unless you blow so hard that the albumen can't escape fast enough, there's very little risk of bursting the shell. But it was seen as primitive and aesthetically displeasing by practitioners of the one-hole method, which came to dominate during the golden age of collecting.

It's worth noting that the one-hole method may be several thousand years older than previously suspected. There is evidence that early humans may have used the one-hole method for emptying ostrich eggs, which would certainly have been practical as the eggs were then used to carry water (see the link at the end of this entry for more).

The hole I made wasn't perfect, the skewer is triangular in section and caught on the edges, but it was roughly the right size and didn't shatter the rest of the shell, which for my second attempt ever I was rather pleased with.

Now, for emptying the egg the contents have to be blended a bit, as the yolk holds together quite strongly and is more than capable of blocking a small hole (this same property makes it easy to extract when making meringues, so I'm not complaining). Where the earliest collectors were satisfied with stiff pieces of grass, I made do with an unfolded paperclip.

Maceration!

Once the contents were well whisked, it was time to actually blow the egg. I know! All this and I haven't even gotten to the good part yet.

I experimented with a number of tools for this as well, as I lacked convenient L-shaped tubes. Emptied ballpoint pens were a non-starter and I didn't have any straws. In the end I just rolled up some paper. It worked rather well!

But there was still a problem: I couldn't muster enough air pressure to force the egg contents out. I choose to believe that this was due to the physical limitations of a paper tube, rather than a comment on the strength of my lungs. Early practitioners of the two-hole method often just blew directly into the egg, which doesn't work particularly well with the one-hole method unless you want a mouthful of yolk. In the end I was forced to do what you are never supposed to do and put the tube inside the egg.

The reason you're not supposed to do this is that if you block the hole then the contents of the egg have nowhere to go. So blowing into the egg increases the pressure on the inside, and without anywhere to release that pressure the shell bursts. I gambled that the uneven hole I made would still allow contents to flow out, and as it happens I was right.

Accidental success is the second best kind of success

The principle behind the one-hole method is that air blown into the egg will rise to the top, forcing the contents down and out of the hole. As long as the hole is below the level of the eggy goo (technical term), it should flow easily. Some collectors held their eggs above bowls of water in case of accidentally dropping them, while one Francis Jourdain (a particularly famous oologist) is said to have held eggs directly above his face when emptying them. As several biographers have noted, Jourdain wore a thick beard. Draw your own conclusions.

So anyway, having hollowed the egg, what did I do next? Well, like any good collector, I washed it.

Inside and out

Eggs have to be washed after blowing, if they aren't then residual contents will putrefy, which not only smells terrible but attracts pests. According to at least one source, washing was also supposed to maintain the egg's colour for longer. Professional collectors (that is, people who aren't me) preferred syringes or, especially in the two-hole method, mouth-to-egg water injection.

Once the egg is washed, it's just a matter of leaving it somewhere where the water can drain out, then treating it with an antiparasitic agent. Back in the day, this would have been camphor, tobacco, mercury compounds, cedar wood, any number of lovely little toxins. The very earliest "modern" collectors of the mid nineteenth century often treated the nests as well, so that the eggs might be stored in their original home (nest collecting, though less common, was also practised). This quickly went out of fashion as the nests tended to collect moisture and damage the eggs.

Some collectors varnished their eggs, which has led me to more than one unfortunately yellowed example in the museum collection. Some examples, such as the great black cormorants below, even seem to have been polished, at least partially. Perhaps this was an attempt to mirror the polishing of seashells, or remove the "chalky" outer layer common to many species? I don't know.

The upper left example is in fact an early form of pokéball

 Since I wasn't planning to keep any of these eggs (the thought crossed my mind, but I don't really have anywhere to keep them), I had no plans to treat them for long term storage. But before I filled them with paint and went trolling for politicians, I wanted to inspect my efforts a bit more closely.

Good to know I'm not the only one cracking up

Well, it could be better. The hole is jagged and unsightly, and even though you can't see them, the cracks made by the skewer show up under the light.

I haven't inspected any of the museum's eggs like this, mostly because I have more pressing tasks but also because eggs are remarkably sensitive to light. According to some sources, all it takes is a few hours of bright sunlight for a delicate pattern to dull (some egg pigments are more volatile than others, however. Chicken eggs are very robust, but many other species do fade quickly in light. Some can even be rubbed off in one's fingers).

I decided to have one more try, if only to make a neater hole and have something to show off properly.

The neatest drilling mark yet!

All for naught

Sadly this was not to be, the third egg broke in much the same way as the first, only it was the skewer that betrayed me instead of the knife.

I learned a lot from this experiment, and my honest opinion is that blowing eggs really isn't as hard as I thought it would be. I know that in parts of the world it's still practiced today, especially for Easter decoration (we always just boiled them), and I wonder what kind of equipment people use. Are there still old egg drills and blowing tubes around, are they sold in shops? In hindsight I should really have looked that up for my report. Ah well. Certainly I think that better equipment would have made the task much easier.

Finally, you might be asking, what did I do with the contents of the eggs? Those who know me know that this is a very silly question.

Natural history is delicious

Anyway, I have much more to talk about and a lot to catch up on, so hopefully you'll be hearing from me again soon.

The information on ostrich eggs came from the University of Cambridge and I thoroughly recommend watching the video on their research here. It's absolutely fascinating.