Editing 1662: Jack and Jill

{{comic
| number    = 1662
| date      = March 30, 2016
| title     = Jack and Jill
| image     = jack_and_jill.png
| titletext = Jill and Jack / began to frack. / The oil boosts their town. / But fractures make / the bedrock shake / and Jack came tumbling down.
}}

==Explanation==
"{{w|Jack and Jill (nursery rhyme)|Jack and Jill}}" is a traditional English nursery rhyme. The rhyme dates back at least to the 18th century, one version even with 15 stanzas.

The first and most commonly known verse is the one referenced by [[Jill]] in the comic as she says the first three lines:
:Jack and Jill
:went up the hill
:To fetch a {{w|wikt:pail|pail}} of water.
:Jack fell down
:and broke his crown,
:And Jill came tumbling after.

The comic makes fun of the counterintuitive idea that Jack and Jill go ''up'' a hill to fetch water, because natural water sources like rivers and streams flow downhill, making them usually found in valleys rather than on top of hills. Thus, it shouldn't be necessary to have to go up a hill to get water. Similarly, if the water is coming from a well, then building a well at the top of a hill seems an odd choice to [[Megan]]. The groundwater table stays at about the same level over smaller areas, so building a well on a hill should require digging further.

However, Megan is probably not aware that since groundwater tends to flow in a similar direction to the slope of the land, it is often considered safer to dig a well uphill from potential sources of runoff (such as outhouses, fields, or septic systems) that may flow down into the underlying pedosphere and porous bedrock below (and perhaps that also being above further impermeable geological layers, as can be seen revealed in instances of  {{w|spring line settlement}}s). In times when populations were more predominantly rural, and probably when the poem was composed, "Always dig your well uphill from the outhouse" was a well-known maxim. Moreover, since it takes more energy to bring water uphill from a well (especially in a pail), there is a long-term advantage to having wells higher than main residential areas, as opposed to lower. (This principle explains why water towers are used, even in cities.) Finally, artesian wells deliver water from confined aquifers, which can sometimes be as close to the surface at higher elevations as at lower ones, easier to access through thin hill-top pedosphere than through deep residual alluvial flood-plain deposits or even ''only'' present in the zone of a particular {{w|Fold (geology)|geological fold}} that helped form the foothill or plateau being described. It is also known for a fortified position upon a defensible high point to have {{w|Castle well|dug an internal well}}, as proof against potential sieges, and perhaps such a useful feature is still the most convenient maintained source - even long after the defensive structure has been abandoned. But Megan may get water from more modern sources, such as a mains water supply grid, and is not familiar with the principles of well placement that Jack and Jill are particularly accustomed to in this instance.

This all said, the predominance of [https://i.ytimg.com/vi/rkQ-MitrSvI/maxresdefault.jpg drawing Jack's and Jill's well at the peak], which is rarely the best place to put any well, makes Megan's (and Randall's) comment understandable. Alternatively, the nursery rhyme may refer to a {{w|Dew pond|dew pond}} (which is more likely to be at the peak than a well), another concept that Megan would not be familiar with, having not grown up in the English countryside.

The title text is [[Randall]]'s own version, a parody of this first verse, where the names have been switched in the first and last line:
:Jill and Jack
:began to frack.
:The oil boosts their town.
:But fractures make
:the bedrock shake
:and Jack came tumbling down.

This version, which may explain why they went up the hill after water, connects the idea to {{w|hydraulic fracturing}} (colloquially "fracking") methods for oil and gas extraction. In these methods, highly pressurized liquids are forced into a given ground stratum (or layer). With enough pressure, the stratum starts to deform and crack. This allows potential gas and oil to flow more freely. The liquid used for fracturing usually also contains materials like sand or ceramics which, once the liquid is removed, will help to maintain the newly formed cracks so as to further allow the desired free movement of oil and gas.

A common {{w|Environmental impact of hydraulic fracturing|side effect of this method}} is that water levels and presence at the surface might be modified. In this comic, water can now be found at the top of the hill. This goes against the usual laws of hydraulics, themselves subject to the laws of gravity, which indicate that water should go down through ground cracks. Thus, water is usually found at the bottom of valleys or hills. But in the comic, fracking at the bottom forces the water up, thus explaining why the kids get water up the hill, which, as [[Megan]] points out, is messed-up {{w|hydrology}}. Also, fracking may cause {{w|induced seismicity}} in the form of {{w|microearthquake}}s, as alluded to in the title text, which is the cause for tumbling down in the title text version.

Randall has previously composed another version of this poem, which was by mistake published in [[Five-Minute Comics: Part 4]]. 
:Jack and Jill went up a hill 
:To fetch a pail of water. 
:Alas, that hill was San Juan Hill, 
:And gruesome was the slaughter. 
In this comic it is made clear that Randall did know that it is possible to have a well on top of a hill, as he has drawn just one of these in the second image. The well in [[561: Well]] and more obviously in [[568: Well 2]] was also found on top of a hill, although it appears this well did not contain any water.

==Transcript==
:[Megan is watching as the two kids Jill (drawn as Jill) and Jack (with spiky hair) are walking by her. Jack has a pail in his hand.]
:Jill: Me and Jack are going up the hill to fetch a pail of water.

:[Megan, standing back alone, calls out after them.]
:Megan: Okay, have fun!

:[Beat panel.]

:Megan: ...Wait. What the ''heck'' is going on with the hydrology around here?

==Trivia==
This comic is the only instance where the character [[Jill]] is given a name, which is why she is referred to as Jill within this wiki. Up until a few years after the comic was posted, she was generally known as Science Girl because of her commonly exhibited personality and interests.

{{comic discussion}}

[[Category:Comics featuring Megan]]
[[Category:Comics featuring Jill]]
[[Category:Kids]]