The Secret Horsepower Race by Calum Douglas (and piston engine discussion)

[Calum Douglas]

I must say it's not that perilous. Just follow the precautions and plan for the future. A few months back a book was released in the German language about a tank built during World War One. It contained new photos and it corrected some old information. As a long-time follower of document releases, I've also seen references to private collections. A few German auction sites regularly feature original award documents and photos for the Luftwaffe. And German eBay has photos of crashed and captured French and British aircraft on a fairly regular basis. One picture can add to the historical record.

This is probably a topic for another thread, so my comment below will be the last on that. I can tell you that one full-time professional archive researcher I know has lost his buisiness and livelyhood, many authors have had their books cancelled, and several other authors are exceptionally worried. If you cannot access files, planning does not assist. I`ve been trying to book 2 days at the Bundesarchiv Lichterfelde, for the last 11months, I promise you it is extremely serious, but equally I of course very much want to be proven quite wrong about my cynicism on this as time goes on.

 

[Pasoleati]

Why didn't RR archives allow copying with camera? I would understand if they banned using flash, but a total ban sounds downright "assholiness".

 

[steelpillow]

I guess R-R are still somewhat stuck in the past. Many archives and libraries used to ban photos. Copyrights, flashlights and assorted disturbing noises were common reasons. Many are easing up, for example the British Library, Science Museum Archive and National Aerospace Library have all eased up significantly over the last few years. This seems mainly because modern digital equipment is far less intrusive, and perhaps also because more institutions seem aware of the public's right to access materials paid for by the public purse. On the other hand, they still hold draconian axes over publishing permissions and are terrified of losing their income stream from copyrights.

But yes, unless you are lucky to find your materials online or in the possession of someone who will send you a scan and permission, much research has ground to a halt. I have a book completed but I cannot progress it because the institution concerned has nobody around to discuss copyright decisions, and publishers are for the most part struggling to get their existing commitments out the door. So I have resorted to a much shorter book on a different topic, with its new information and image permissions obtained via personal contact, which I am in process of self-publishing.

 

[Hood]

Not to derail the thread further, but there is likely to be a serious downturn in new history books of all genres over the next couple of years.
Even volunteers can't access their own archives at the moment. So for now the situation is a case of making do with what resources you already have and hoping that you might get access again when things improve. Probably many authors have had their research delayed at least a year or two at minimum.
I'm lucky that my book is in the final stages of writing but even so sacrifices have had to be made. Its a shame but those are the hard decisions we are faced with.
On the bright side, by 2022 publishers might be clamouring for new books to fill their 2023 catalogues.

 

[A Tentative Fleet Plan]

I'm lucky that my book is in the final stages of writing but even so sacrifices have had to be made.

What is your book going to be covering?

 

[edwest4]

I must say it's not that perilous. Just follow the precautions and plan for the future. A few months back a book was released in the German language about a tank built during World War One. It contained new photos and it corrected some old information. As a long-time follower of document releases, I've also seen references to private collections. A few German auction sites regularly feature original award documents and photos for the Luftwaffe. And German eBay has photos of crashed and captured French and British aircraft on a fairly regular basis. One picture can add to the historical record.

This is probably a topic for another thread, so my comment below will be the last on that. I can tell you that one full-time professional archive researcher I know has lost his buisiness and livelyhood, many authors have had their books cancelled, and several other authors are exceptionally worried. If you cannot access files, planning does not assist. I`ve been trying to book 2 days at the Bundesarchiv Lichterfelde, for the last 11months, I promise you it is extremely serious, but equally I of course very much want to be proven quite wrong about my cynicism on this as time goes on.

I have been in book publishing for decades. This is all I do for a living. When the current situation hit, a series of normal and average reactions occurred. However, it was important to begin navigating as quickly as possible. In the US, the majority of the distribution network collapsed. But there were exceptions, like Amazon. In the meantime, the other book distributors had to begin to develop a course of action, often, more than one. No one wanted to lose their livelihood.

Today, two vaccines are being distributed and the pace of vaccinations is accelerating. Next month, in the US, a third vaccine should be approved.

Prior to 2020, I know of books that were cancelled for no apparent reason. One researcher contacted me to see if I could help him in some way to get his book published through a particular publisher. I could not help. In the case of the book, The History of Military Computers, a cover appeared but no book. I called the publisher. It had been cancelled without explanation.

 

[Calum Douglas]

Why didn't RR archives allow copying with camera? I would understand if they banned using flash, but a total ban sounds downright "assholiness".

You are only permitted to make B&W copies by photocopier (main issue being its about 10x slower than a camera).

I tried to get at some fuel development papers held by "The Royal Society", I gave up on my plans to travel 400miles when they explained you were only allowed to make notes by pencil... (I`m serious)

That is pretty much like some nonsense Hollywood film where someone gets into the Vatican archives or something. Anyway I`ll try not to rant about it here.

 

[Pasoleati]

Wow! Makes no sense, as using camera is actually less damaging to the documents than photocopier (=using camera requires less manhandling the docs).

That Royal Society dictate is true insanity. Perhaps they should be made an offer they cannot refuse...

 

[Hood]

Wow! Makes no sense, as using camera is actually less damaging to the documents than photocopier (=using camera requires less manhandling the docs).

That Royal Society dictate is true insanity. Perhaps they should be made an offer they cannot refuse...

The National Archives at Kew only allow you a pencil too. And no eraser... and no pencil sharpener (top tip, take two pencils cause if you go blunt or snap you have a spare).
Of course you can take a laptop in to type (though in my experience researchers with laptops tend to never actually do much research!).

I think they are worried about accidently pen/ink marks and the not impossible case of some goof making additions in pen to documents. Some idiots have tried to insert fake documents into files (I think there was a case recently involving a Churchill file) and others have stolen pages (the imfamous guy stealing 617 Sqn stuff to sell on) - they check the papers you bring in and out.

I'm lucky that my book is in the final stages of writing but even so sacrifices have had to be made.

What is your book going to be covering?

Post-war British training aircraft.

 

[overscan (PaulMM)]

The National Archives at Kew only allow you a pencil too. And no eraser... and no pencil sharpener (top tip, take two pencils cause if you go blunt or snap you have a spare).
Of course you can take a laptop in to type (though in my experience researchers with laptops tend to never actually do much research!).

Well, yes, but you can use a digital camera to copy the whole file then read and make notes at your leisure later at home, with pens if you like.

 

[Hood]

The National Archives at Kew only allow you a pencil too. And no eraser... and no pencil sharpener (top tip, take two pencils cause if you go blunt or snap you have a spare).
Of course you can take a laptop in to type (though in my experience researchers with laptops tend to never actually do much research!).

Well, yes, but you can use a digital camera to copy the whole file then read and make notes at your leisure later at home, with pens if you like.

Of course, that's the most efficient way (what we used to call in my Master's class a 'smash and grab').
I tend to do a mixture of both camera and written notes while I'm in an archive.

My point was that archives only using pencils for physical notetaking is not rare and there are good reasons for doing so. Reasons for not allowing digital cameras are less defensible, but I assume they are worried about copyright (I assume the Royal Society wouldn't want some of its rarer stuff turning up on Flickr and the like) and the loss of copying fees denies them a modest income stream.

 

[steelpillow]

Part of the issue is traceability. Copyrights are one of their few income streams. If a copy of a document appears in the wild, a photocopy or scan made on their machine provides traceability back to the violator. Moreover, it embodies the "artistic" copyright of the archive, which dates from the time of the scan and is independent of any author's copyright which may have lapsed. Handheld snaps of a document examined by several visitors are in this respect the visitor's artistic copyright and, even if the content is still in copyright, are far harder to attribute.

One may need multiple permissions. For example, were I to reproduce a page from JW Dunne's posthumous autobiography Intrusions? and I sourced it from the JW Dunne Collection in the Science Museum's archives, I would need copyrights from; his widow's heirs (as she owned its original copyright but died less than 70 years ago), the publisher (as they own the page's artistic copyright), and the Museum (as they would own the scan's artistic copyright).

What makes this worse is that some organisations contract out the reproduction to a commercial company. Obtaining a copy of something then includes the commercial cost of communicating with the archivists, handling of the rare document by qualified staff, processing the scan, sending a copy plus cost to you, administering the whole exercise and topping it all with a profit margin. A single document in a successful book can rack up a four-figure sum in initial cost plus volume royalties. Multiply that by a mere few dozen selected from a single acquisition of 30,000 such.... This is what is crippling my ability to publish materials which the Science Museum spent a lot of money on with the express purpose of preserving them in order that their contents might be made widely available.

Quite how Morton's authors such as Calum here and newsdeskdan are able to get round such obstacles is something I would love to know.

However hand-copying of text does not breach artistic copyrights and the text of many historic documents is out of copyright. Most material originated by Dunne went out only a couple of years ago. So I can for example type out his "I have solved the secret of flight" letter in full, but I cannot include a scan of the original typescript.

Insanity comes in many forms.

 

[Foo Fighter]

"Insanity comes in many forms". Sadly, insanity has far too many 'fans'.

 

[Calum Douglas]

I recieved an email question from a reader today, on page 106/107 regarding the DB 608 engine. I wrote "possibility for reversing the propeller direction". This is because they made two versions, one with an intermediate reduction gear, I did not mean to imply they could do that "in-flight". I`ll consider re-wording it in the next printing. (original German above for those so-inclined - dated 20th November 1939 from Daimler-Benz to the RLM).

 

[Foo Fighter]

For me it read rather like the RR engines fitted to the Hornet and Sea Hornet with each engine reversing rotation point at the build point allowing torque effect reduction. My own take on it Not sure how much you could say but, if you were to write a book of your experience with Mercedes F1 engines and the whole process, I would very happily buy it and I know more than a few F1 fans out there who would also be interested. Another niche I know but I think it would be at least a going concern. Engines you see, we cannot get enough of 'em or reading about 'em either.

Stay well, Sir. What you do is appreciated by many.

 

[SeaslugMk2]

The National Archives at Kew only allow you a pencil too. And no eraser... and no pencil sharpener (top tip, take two pencils cause if you go blunt or snap you have a spare).
Of course you can take a laptop in to type (though in my experience researchers with laptops tend to never actually do much research!).

Or take a propelling pencil and a pack of spare leads -which is what I do. Along with a digital camera.

SRJ.

 

[steelpillow]

Well, yes, but you can use a digital camera to copy the whole file then read and make notes at your leisure later at home, with pens if you like.

The British Library, National Aerospace Library and Science Museum have all opened up and allowed this in the last few years, for most of their documents anyway. Use of flash tends to be banned though, so you need a decent digital camera with good low-light resolution (as I have found to my cost, a cheaper camera may offer good resolution and low-light capability, just not together in the same image...).

 

[Calum Douglas]

Well, yes, but you can use a digital camera to copy the whole file then read and make notes at your leisure later at home, with pens if you like.

The British Library, National Aerospace Library and Science Museum have all opened up and allowed this in the last few years, for most of their documents anyway. Use of flash tends to be banned though, so you need a decent digital camera with good low-light resolution (as I have found to my cost, a cheaper camera may offer good resolution and low-light capability, just not together in the same image...).

I bought a Sony DSC camera at reasonable expense, mostly because it had a remote trigger and also a flip-screen, so I could see the framing from a sitting position with the camera on a table-arm clamp. However, it is rubbish in low-light, even it its class, which I discovered much to my distaste, so I had to carry two LED softlights with me to archives to get good pics. Only a couple of archives let me carry the lights in, so that was a pain. I`ve never had a grand spare to get an upgraded "archive camera". For text its perfectly adequate, but when it came to using my photos of images and diagrams, it was... upsetting. I put about 180 hours of photo-editing into the book images, however, I`d have needed to do that even with a better camera as usually it was correcting page warping, or problems in the original image (or dealing with the lovely reflective plastic wallets that Kew loves to enclose all photos inside).

 

[steelpillow]

@Calum Funny that, my lemon is a Sony too.

 

[Dagger]

I`ll consider re-wording it in the next printing.

Is there already a next printing scheduled?
If so what is the deadline for any comments, suggestions and found typing errors from our side?

 

[Calum Douglas]

I`ll consider re-wording it in the next printing.

Is there already a next printing scheduled?
If so what is the deadline for any comments, suggestions and found typing errors from our side?

We`ve only got about 170 left of the 2nd printing, so 3rd printing will commence in about.... 6 weeks ?

Anything you let me know of before then, I`ll address.

 

[Calum Douglas]

I forgot to mention, I`ve added a page to my website with 100 images from the book uploaded in hi-res, I chose the 100 charts and diagrams which were the smallest and most difficult to read in the book, so you can look online or download etc. I have watermarked them (reasonably gently) as sadly certain persons have demonstrated a total inability to avoid immediately downloading all new WW2 aviation images then reposting elsewhere without any references and claiming credit for "finding" them on said forum. So a case of a couple spoiling it for everyone, however, I am certain that the watermark is not so bad as to impair your ability to make out missing details.

The Secret Horsepower Race: Image Archive – Calum Douglas

 

[Dagger]

................ I have watermarked them (reasonably gently) .................

In my opinion you have been much to gentle with the watermarks. Most are hardly or not visible at all.
Watermarks should have been in colour.

I have not yet had time to study the whole book (only the first 6 chapters, up to page 305) but it is one of the few books that I bought through the years that exceeds my expectations.
Sofar the only image that I had trouble reading was the one on page 218 right, specifically part of the text along some lines. Now I can see on your website that it says: " Höchst " (highest, maximum). That graph does not seem to have a watermark at all, like several others.

I do have some questions about how to interpret some graphs, that hopefully you can explain:

page 20: the horizontal axis shows numbers that seem to be some kind of horsepowers, but it does not say what. My best guess is Indicated Horsepower, IHP. The Corrected Horsepower on the left hand vertical axis is then the actual shaft HP (BHP) after subtracting friction (and other) losses inside the engine and the power consumption of the supercharger. Is that correct?

page 78, graph: Which aircraft and engine? Is the red line in the graph for a certain aircraft speed, and if so, what speed? Or is it supposed to be applicable for any speed?

page 196, graph on the left: horizontal axis is missing. My guess is that it runs up to an altitude of 10 km.

page 252: The lines for Merlin XX and Merlin 61 look the same in style, so the reader has to guess which is which. The lines with +18LB would be for Merlin 61 and the ones with +12LB for Merlin XX ? But what does 0" mean, as in: +18LB/0" ?

page 253, graph: the red line for Latest Spitfire IX is indicated to be for 15 lb boost 2000 RPM. Presumably that 2000 is a writing error? But then: why did they mention it as none of the other lines mentions the RPM ?

page 301, graph on the left: What do the lines that go sky high with increased altitude represent? What is the right hand scale? Drag in kg (force) per HP ? The text around it is about radiator drag and mentions at btm of page: "...... -250hp for the DB 605 A-C combat performance and -100hp Merlin 61". I don't see how that can be derived from the graph.

 

[SeaslugMk2]

Well, yes, but you can use a digital camera to copy the whole file then read and make notes at your leisure later at home, with pens if you like.

The British Library, National Aerospace Library and Science Museum have all opened up and allowed this in the last few years, for most of their documents anyway. Use of flash tends to be banned though, so you need a decent digital camera with good low-light resolution (as I have found to my cost, a cheaper camera may offer good resolution and low-light capability, just not together in the same image...).

I bought a Sony DSC camera at reasonable expense, mostly because it had a remote trigger and also a flip-screen, so I could see the framing from a sitting position with the camera on a table-arm clamp. However, it is rubbish in low-light, even it its class, which I discovered much to my distaste, so I had to carry two LED softlights with me to archives to get good pics. Only a couple of archives let me carry the lights in, so that was a pain. I`ve never had a grand spare to get an upgraded "archive camera". For text its perfectly adequate, but when it came to using my photos of images and diagrams, it was... upsetting. I put about 180 hours of photo-editing into the book images, however, I`d have needed to do that even with a better camera as usually it was correcting page warping, or problems in the original image (or dealing with the lovely reflective plastic wallets that Kew loves to enclose all photos inside).

At least Kew has some desks with camera stands which allow long exposure times; my cheap Fuji JV500 seems to cope although the auto-focus seems to wander off at times! My main beef is the colour cast from the fluorescent tubes.

SRJ.

 

[Hobbes]

In my opinion you have been much to gentle with the watermarks. Most are hardly or not visible at all.
Watermarks should have been in colour.

The watermark should use a color that's also used in the drawing itself. If you use a different color, it becomes pretty easy to remove the watermark.

 

[Calum Douglas]

................ I have watermarked them (reasonably gently) .................

In my opinion you have been much to gentle with the watermarks. Most are hardly or not visible at all.
Watermarks should have been in colour.

I have not yet had time to study the whole book (only the first 6 chapters, up to page 305) but it is one of the few books that I bought through the years that exceeds my expectations.
Sofar the only image that I had trouble reading was the one on page 218 right, specifically part of the text along some lines. Now I can see on your website that it says: " Höchst " (highest, maximum). That graph does not seem to have a watermark at all, like several others.

I do have some questions about how to interpret some graphs, that hopefully you can explain:

page 20: the horizontal axis shows numbers that seem to be some kind of horsepowers, but it does not say what. My best guess is Indicated Horsepower, IHP. The Corrected Horsepower on the left hand vertical axis is then the actual shaft HP (BHP) after subtracting friction (and other) losses inside the engine and the power consumption of the supercharger. Is that correct?

page 78, graph: Which aircraft and engine? Is the red line in the graph for a certain aircraft speed, and if so, what speed? Or is it supposed to be applicable for any speed?

page 196, graph on the left: horizontal axis is missing. My guess is that it runs up to an altitude of 10 km.

page 252: The lines for Merlin XX and Merlin 61 look the same in style, so the reader has to guess which is which. The lines with +18LB would be for Merlin 61 and the ones with +12LB for Merlin XX ? But what does 0" mean, as in: +18LB/0" ?

page 253, graph: the red line for Latest Spitfire IX is indicated to be for 15 lb boost 2000 RPM. Presumably that 2000 is a writing error? But then: why did they mention it as none of the other lines mentions the RPM ?

page 301, graph on the left: What do the lines that go sky high with increased altitude represent? What is the right hand scale? Drag in kg (force) per HP ? The text around it is about radiator drag and mentions at btm of page: "...... -250hp for the DB 605 A-C combat performance and -100hp Merlin 61". I don't see how that can be derived from the graph.

20: The X axis is crankshaft rpm, this seems to have been inadvertently trimmed off by the page-setter.... I`ll have to get that fixed in the next printing. Sorry !



78: This is a generic graph to show how the various aspects are related, it is not about any specific engine or aircraft.

196: The major graduations are 1km, so the 2nd "peak" is 5km, and the RHS of the page is 10km, yes.

252: Its an original graph and thats how it looks. I couldn't afford to re-do every single graph. I took the view with that one, that it ought to be
not asking too much for the reader to imagine that the Merlin-61 is the line with the markedly higher performance. The lb/0" is in fact a not very
well drawn square, for "square inches". You can see it a bit better on this old oil pressure gauge.



253: It does actually say "3000rpm", its just badly written in the original pencil. If you download the image I`ve provided on my website, and zoom right in, you`ll see.
Its probably not mentioned anywhere else as its likely all the curves are 3000rpm.

301: The axis are on the graph, left hand Y axis is "PS", right hand Y axis is "kg/ps" and the x axis is altitude. Remember, in German a comma in numbers is the same
as our decimal point, so for example on the right hand vertical axis: 2,000 is 2.000 to us. Its the kg of engine weight per propulsive power unit (in this case PS),
that obviously rockets upwards as altitude increases as weight remains static but power goes down. The comment in the original German letter, is perhaps not well worded, but what he`s saying is (paraphrasing) "Looking at this engine chart, where the Merlin-61 has two points plotted, the Merlin-61 is obviously better than
the DB605A-C, once you then factor in the increased drag we know the DB engine has because of the bigger radiator, this superiority is will be even more pronounced".

It could probably do with an end-note to clear that up, but I`ve not intended to imply that the chart showing the aerodynamic drag IS the one shown in the book. (the chart wasnt in Professor Messerschmitts correspondance file, where I got the letter, so it may well never have existed in the letter and could be something the Professor just had to hand when he wrote that letter to Fritz Nallinger, and was just making an off-hand remark about). I hope that makes sense ?

 

[steelpillow]

Tip on watermarks: Faint colours can often be removed with no more than a little contrast enhancement, followed if need be by the reverse greying back down to restore halftones. Use a grid of black dots a little bigger than the smallest discernible features, to give a light grey effect. Attempts to blur the dots out to lighten them ready for removal will also grey-out and remove the fine details.

Most graphics packages such as Inkscape or Gimp allow you to apply textures in this way, though you may need to convert your watermark to an interim path or bitmap format first.

 

[Foo Fighter]

Sorry to be negative but those pictures on the web site are not particularly good, imoho.

 

[Calum Douglas]

Sorry to be negative but those pictures on the web site are not particularly good, imoho.

I`ve updated it using a different wordpress plugin, as the standard "gallery" caps the resolution - and then re-uploaded the entire 100 image gallery.

I`m wondering a bit why I bother with all this, even with the resolution capped I thought they were fine.

 

[F119Doctor]

I just finished the book, and it was an excellent and informative read. A couple of thoughts and notes:

1. Bottom of Page 406 - the sentence "In these last few months the British fighters experienced a rejuvenated role....." is repeated. One of these sentences should be deleted in the next printing

2. You discussed the development of copper-lead-indium plain bearings in England, but the use of silver-lead-indium bearings by Allison and Pratt & Whitney just seemed to appear in the text. No discussion on their development or relative merits vs. the copper-lead-indium bearings. I know that one of the issues is the inability to use the anti-wear additives Zinc dialkyldithiophosphates (ZDDP) with silver bearings due to the corrosion caused by the sulfur in ZDDP. This is one reason that silver is not used in modern road engines bearings, even though I believe the silver-lead-indium bearings were superior to the copper design.

3. I realize that you deferred to Graham White's "Pratt & Whitney's Dependable Masterpiece" for the in-depth story of the R-2800 development. But I think you could have included a short discussion on some of the advancements made on that engine, such as:

- the development of 2x crank speed balance rings to counteract 2nd order vibrations (many years before Mitsubishi put the first balance shafts on 4 cylinder in-line engines for the same purpose)

- the development of finely spaced machined cooling fins on forged cylinder heads in the C model R-2800s to make possible the boost levels needed for the 2800 hp levels achieved, combating the high cylinder head temperatures you discussed as a limitation for this air cooled design

- P&W used a unique method of injecting fuel from the pressure carburetor. The single point injector placed the fuel into a cavity inside the bore of the supercharger impeller. Centrifugal action distributed the fuel evenly around the cavity, and then out thru evenly space holes in the impeller, where the fuel entered the airstream approximately halfway to the rim. This provided even distribution of the fuel air mixture, with rapid evaporation and cooling of the charge.

- While your book is focused on the European theater, where the P-47 was the only R-2800 powered fighter, it might have been worthwhile to note that P&W successfully developed 2 speed, 2 stage intercooled superchargers with for the Hellcat and Corsair for the US Navy in the Pacific theater, the later versions of which went to variable speed hydraulic couplings similar to those developed by the Germans.

 

[Foo Fighter]

One or more have been replaced by higher quality images, the Centaurus and Mosquito images were no doubt the worst. The Mosquito image has been replaced and gone from page one to page four. The text on the Centaurus is still blurred, also on page four and cannot be enlarged to gain clarity.

I don't actually expect the highest quality images but thought I would point out your point that the images were higher quality. Not all were. No intention of making this the big deal of the century.

 

[Calum Douglas]

Thats because the original photograph is blurred. I really cannot fathom your comment that "not all were", excuse me but I`ve provided you with
full page size images which in the book are in places about 2.5" squared, how you can claim thats poor, is utterly beyond me. Really, it is.

 

[Foo Fighter]

I think you need to take a moment and relax. Try using a 'sotto voce' method of internal 'voice' when reading, you will do better.

 

[Dagger]

OK, so the graph on page 301 is not the graph mentioned in the quote. My confusion was caused by the graph being placed inside the quote. In a next printing maybe better move it outside the quote and modify its caption.

A few more unclear quotes:

Page 213 bottom right, inside quote: ".... is indicated on curve sheets 2 and 3. (e.g. page 228) .... "
Presumably the curves are on page 228 of the original document. I don't think they are in the book somewhere. In that case it may be better to modify or delete the quote.

Page 213 bottom left, inside quote: ".... using the existing Benzene carburettor ...."
Is Benzene here a typo? Should that be Bendix or a similar name?

Page 227 left, inside quote: ".... benzol and synthetic benzene ..................... leaded benzene shows a high increase ................ while the paraffinic benzene remains stable .............."
Obviously paraffinic benzene does not exist as benzene is aromatic.
It would be interesting for me to see the original German text of this quote as I suspect that the German word Benzin may have been mistranslated two or three times here. The German word Benzin means gasoline, not benzene which in German is Benzol, but that word can also refer to a coal tar product rich in aromatics (benzene, toluene, xylene).
Please check with the original German document.

 

[overscan (PaulMM)]

Sorry to be negative but those pictures on the web site are not particularly good, imoho.

I`ve updated it using a different wordpress plugin, as the standard "gallery" caps the resolution - and then re-uploaded the entire 100 image gallery.

I`m wondering a bit why I bother with all this, even with the resolution capped I thought they were fine.

I didn't see it before you reuploaded, but the new images are all perfectly high resolution. Any remaining issues are from the original source or the digital camera copy, not the upload.

Feedback should be generally understood as intended to be constructive on this forum. However, the wording by Foo Fighter was a little harsh.

Compare:

"Sorry to be negative but those pictures on the web site are not particularly good, imoho."

"That's really helpful, thanks Callum. Some of the more images would be more readable if it were possible to upload them at a higher resolution".

 

[Foo Fighter]

Feedback should be generally understood as intended to be constructive on this forum. However, the wording by Foo Fighter was a little harsh.

Compare:

"Sorry to be negative but those pictures on the web site are not particularly good, imoho."

"That's really helpful, thanks Callum. Some of the more images would be more readable if it were possible to upload them at a higher resolution".

Thank you for the positive feedback, you are quite correct as ever and I shall take it on board. My recollection was "Some ofthose pictures on the web site " but my memory is obviously faulty. I shall work at improving my posts.

Sorry folks, I let you all down.

 

[Calum Douglas]

OK, so the graph on page 301 is not the graph mentioned in the quote. My confusion was caused by the graph being placed inside the quote. In a next printing maybe better move it outside the quote and modify its caption.

A few more unclear quotes:

Page 213 bottom right, inside quote: ".... is indicated on curve sheets 2 and 3. (e.g. page 228) .... "
Presumably the curves are on page 228 of the original document. I don't think they are in the book somewhere. In that case it may be better to modify or delete the quote.

Page 213 bottom left, inside quote: ".... using the existing Benzene carburettor ...."
Is Benzene here a typo? Should that be Bendix or a similar name?

Page 227 left, inside quote: ".... benzol and synthetic benzene ..................... leaded benzene shows a high increase ................ while the paraffinic benzene remains stable .............."
Obviously paraffinic benzene does not exist as benzene is aromatic.
It would be interesting for me to see the original German text of this quote as I suspect that the German word Benzin may have been mistranslated two or three times here. The German word Benzin means gasoline, not benzene which in German is Benzol, but that word can also refer to a coal tar product rich in aromatics (benzene, toluene, xylene).
Please check with the original German document.

The "page 228" quote on page 213, isnt referring to a page in the original report, it is supposed to reference a chart in my book on that page,
somehow its changed in editing somewhere and the text has escaped being updated. I`ll have to have a look and see which page the
chart is now located on.

Yes on page 213, it should be "Bendix" carburettor, I`ll have to fix that in the 3rd printing.

Page 227, may be a mistake in the original translation, which was done by British Air Intelligence (sometimes the translator wasnt a technical specialist in the area concerned, and so they`re not infallible). Luckily although I didnt translate that one myself, I do have the original German too, so I`ll have to go back and look which wont happen today, the requisite changes needed will go into the 3rd print.
Thanks for spotting it.

 

[Arjen]

I just downloaded all images.

I forgot to mention, I`ve added a page to my website with 100 images from the book uploaded in hi-res, I chose the 100 charts and diagrams which were the smallest and most difficult to read in the book, so you can look online or download etc.

Eminently readable now. Thank you for uploading.

 

[Dagger]

In the chapters that I read so far (1 thru 6) I had little trouble reading the images, but for some of them I used a magnifying glass. For me a dozen uploaded larger images would have been sufficient.

Now that Calum uploaded a lot of images I can see that the full size version of the graph on page 98 has on its left a legend defining a, b and c. Until now I deducted them from the text on top of page 99.
In a next printing it may be best to include (a), (b) and (c) at appropriate places in that text as that will give less layout problems than replacing the present graph by the much wider one with the legend, as that would mess up page breaks and consequently page numbering of the rest of the book. Just my thoughts, Calum to decide of course.

A few more comments from my notes:

Page 25 top right: ".... mixed with 90 % iso-octane ...." that should be 10 %

Page 55 btm left: "The charge temperatures on the boosted Merlin II were 92° as opposed to 70° on the Kestrel"
I expect that °C is meant, as °F would be rather low boost temperature, but best to allways add units.

Page 184 middle right: "..... 75° maximum temperature limit ....."
I am sure that is °C but better add it anyway.

Page 68 btm right: ".... all at a boost air pressure of 40 °C ."
Is here boost air temperature meant? Or boost air pressure of 40 ..... (in appropriate pressure units) ?

Page 216 top left: "Maximum boost pressure was 44.2 in of mercury."
Was that 44.2 inch absolute, so +7 psi boost? Or 44.2 inch above 1 atm, so +21.7 psi boost?
I'm not an expert on the Sabre engine, but +7 psi seems low to me and +21.7 psi seems high, so I wonder which is correct here.

EDIT: just to be clear: I have the first printing of the book, some of my comments may already be included in the second printing which I never saw.

 

[Calum Douglas]

In the chapters that I read so far (1 thru 6) I had little trouble reading the images, but for some of them I used a magnifying glass. For me a dozen uploaded larger images would have been sufficient.

Now that Calum uploaded a lot of images I can see that the full size version of the graph on page 98 has on its left a legend defining a, b and c. Until now I deducted them from the text on top of page 99.
In a next printing it may be best to include (a), (b) and (c) at appropriate places in that text as that will give less layout problems than replacing the present graph by the much wider one with the legend, as that would mess up page breaks and consequently page numbering of the rest of the book. Just my thoughts, Calum to decide of course.

A few more comments from my notes:

Page 25 top right: ".... mixed with 90 % iso-octane ...." that should be 10 %

Page 55 btm left: "The charge temperatures on the boosted Merlin II were 92° as opposed to 70° on the Kestrel"
I expect that °C is meant, as °F would be rather low boost temperature, but best to allways add units.

Page 184 middle right: "..... 75° maximum temperature limit ....."
I am sure that is °C but better add it anyway.

Page 68 btm right: ".... all at a boost air pressure of 40 °C ."
Is here boost air temperature meant? Or boost air pressure of 40 ..... (in appropriate pressure units) ?

Page 216 top left: "Maximum boost pressure was 44.2 in of mercury."
Was that 44.2 inch absolute, so +7 psi boost? Or 44.2 inch above 1 atm, so +21.7 psi boost?
I'm not an expert on the Sabre engine, but +7 psi seems low to me and +21.7 psi seems high, so I wonder which is correct here.

EDIT: just to be clear: I have the first printing of the book, some of my comments may already be included in the second printing which I never saw.

I`ll correct the bit on page 25, and perhaps add some clarification symbols for Deg C. On pg 216 yes, +7PSI (i.e. gauge) is absolutely the correct figure for the Sabre at that time.

The bit on page 68 just isnt worded very well, I think "of" should really be "at".