diff --git a/CMakeLists.txt b/CMakeLists.txt
index 58fa73f..7e713e1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,6 +22,7 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
         -Wpedantic
         -Wconversion
         -Wshadow
+        -fno-rtti
     )
 endif()
 
@@ -35,11 +36,12 @@ set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 # Add Chapters
 # ------------------------------------------------------------
 
+add_subdirectory(SetupChapter)
 add_subdirectory(Common)
-add_subdirectory(Chapter4-TypeErasure)
-add_subdirectory(Chapter8-SensorPipelines)
-add_subdirectory(Chapter9-SystemController)
-add_subdirectory(Chapter10-Reactor)
-add_subdirectory(Chapter11-FusionTiming)
-add_subdirectory(Chapter12-DeterministicFusionAndOutput)
+add_subdirectory(Chapter3-TypeErasure)
+add_subdirectory(Chapter7-SensorPipelines)
+add_subdirectory(Chapter8-SystemCompositionAndControl)
+add_subdirectory(Chapter9-IntegratingExternalInputs)
+add_subdirectory(Chapter10-FusionTiming)
+add_subdirectory(Chapter11-DeterministicFusionAndOutput)
 add_subdirectory(ExternalDataSource)
diff --git a/Chapter7-SensorPipelines/CMakeLists.txt b/Chapter7-SensorPipelines/CMakeLists.txt
index 6846e3c..42298de 100644
--- a/Chapter7-SensorPipelines/CMakeLists.txt
+++ b/Chapter7-SensorPipelines/CMakeLists.txt
@@ -10,6 +10,8 @@ add_executable(SensorPipelineDemo
     include/PositionProducer.h
     include/PositionConsumer.h
     include/SensorPipeline.h
+    include/BurstySensorPipelineIntervals.h
+    include/DefaultSensorPipelineIntervals.h
     src/SensorPipeline.cpp
     src/PositionConsumer.cpp
     src/PositionProducer.cpp
diff --git a/Chapter7-SensorPipelines/README.md b/Chapter7-SensorPipelines/README.md
index 00891d1..2c9f820 100644
--- a/Chapter7-SensorPipelines/README.md
+++ b/Chapter7-SensorPipelines/README.md
@@ -1 +1 @@
-This repository accompanies Chapter 8 of _Designing Deterministic Systems with Modern C++_.
+This repository accompanies Chapter 7 of _Designing Deterministic Systems with Modern C++_.
diff --git a/Chapter7-SensorPipelines/include/BurstySensorPipelineIntervals.h b/Chapter7-SensorPipelines/include/BurstySensorPipelineIntervals.h
new file mode 100644
index 0000000..838baca
--- /dev/null
+++ b/Chapter7-SensorPipelines/include/BurstySensorPipelineIntervals.h
@@ -0,0 +1,32 @@
+#pragma once
+
+#include <chrono>
+
+#include "SensorPipeline.h"
+
+// A test scaffold for the producer loop that allows for bursts of measurements,
+// the idea is to _force_, from time to time, the producer to block on emplacing
+// a measurement to a full queue
+static
+SensorPipelineIntervals& getBurstyIntervals()
+{
+    static constexpr long burstInterval = 1000;
+    static constexpr long burstOf = 300;
+    static long count {0};
+
+    struct Bursty : public SensorPipelineIntervals
+    {
+        std::chrono::nanoseconds pollingInterval() const
+        {
+            return std::chrono::microseconds(count++ % burstInterval <= burstOf);
+        }
+
+        std::chrono::nanoseconds blockedWaitingInterval() const
+        {
+            return std::chrono::microseconds(50);
+        }
+    };
+
+    static Bursty bursty {};
+    return bursty;
+}
diff --git a/Chapter7-SensorPipelines/include/DefaultSensorPipelineIntervals.h b/Chapter7-SensorPipelines/include/DefaultSensorPipelineIntervals.h
new file mode 100644
index 0000000..c3c196e
--- /dev/null
+++ b/Chapter7-SensorPipelines/include/DefaultSensorPipelineIntervals.h
@@ -0,0 +1,19 @@
+#pragma once
+
+#include <chrono>
+
+#include "SensorPipeline.h"
+
+
+static
+SensorPipelineIntervals& getDefaultIntervals()
+{
+    struct Defaults : public SensorPipelineIntervals
+    {
+        std::chrono::nanoseconds pollingInterval() const { return std::chrono::microseconds(1000); }
+        std::chrono::nanoseconds blockedWaitingInterval() const { return std::chrono::microseconds(50); }
+    };
+
+    static Defaults defaults {};
+    return defaults;
+}
diff --git a/Chapter7-SensorPipelines/include/GpsMeasurement.h b/Chapter7-SensorPipelines/include/GpsMeasurement.h
deleted file mode 100644
index e69de29..0000000
diff --git a/Chapter7-SensorPipelines/include/SensorPipeline.h b/Chapter7-SensorPipelines/include/SensorPipeline.h
index 5fd18b1..fbf7c91 100644
--- a/Chapter7-SensorPipelines/include/SensorPipeline.h
+++ b/Chapter7-SensorPipelines/include/SensorPipeline.h
@@ -1,13 +1,17 @@
 #pragma once
 
 #include <atomic>
+#include <chrono>
 #include <cstddef>
 #include <thread>
 
 #include "readerwriterqueue.h"
+#include "Counters.h"
 
 #include "AnyMeasurement.h"
 
+class SensorPipelineIntervals;
+
 //
 // A simple, fixed-topology pipeline:
 // Producer thread -> SPSC queue -> Consumer thread
@@ -15,15 +19,21 @@
 class SensorPipeline
 {
 public:
-    explicit SensorPipeline(std::size_t capacity);
+    explicit SensorPipeline(std::size_t capacity); // creates this "holder" but doesn't start work
+    explicit SensorPipeline(std::size_t capacity,
+                            const SensorPipelineIntervals& producerIntervals,
+                            const SensorPipelineIntervals& consumerIntervals);
     ~SensorPipeline();
 
     SensorPipeline(const SensorPipeline&) = delete;
     SensorPipeline& operator=(const SensorPipeline&) = delete;
 
-    void start();
-    void stop();
-    void join();
+    void start(); // create pipeline (including its threads) and start flow
+    void stop();  // _request_ work to end (does not block)
+    void join();  // wait for completion of pipeline (blocks) and end threads (and resources)
+    // ...now SensorPipeline is safe to destruct
+
+    void status(std::ostream& os);
 
 private:
     void producerLoop();
@@ -34,4 +44,20 @@ class SensorPipeline
     std::thread m_producerThread;
     std::thread m_consumerThread;
     std::atomic<bool> m_running { false };
+
+    const SensorPipelineIntervals& m_producerIntervals;
+    const SensorPipelineIntervals& m_consumerIntervals;
+
+    Counter producer_enqueued;
+    Counter producer_blocked;
+    Counter consumer_blocked;
+    Counter consumer_dequeued;
+};
+
+struct SensorPipelineIntervals
+{
+    virtual std::chrono::nanoseconds pollingInterval() const = 0;
+    virtual std::chrono::nanoseconds blockedWaitingInterval() const = 0;
+
+    virtual ~SensorPipelineIntervals() = default;
 };
diff --git a/Chapter7-SensorPipelines/src/SensorPipeline.cpp b/Chapter7-SensorPipelines/src/SensorPipeline.cpp
index eb1f467..fca49c4 100644
--- a/Chapter7-SensorPipelines/src/SensorPipeline.cpp
+++ b/Chapter7-SensorPipelines/src/SensorPipeline.cpp
@@ -12,6 +12,7 @@
 #include "MeasurementTypes.h"   // weather::Position, MeasurementHeaderV1, SourceId
 #include "PositionProducer.h"
 #include "PositionConsumer.h"
+#include "DefaultSensorPipelineIntervals.h"
 
 namespace
 {
@@ -23,13 +24,24 @@ std::uint64_t nowNs() noexcept
         std::chrono::duration_cast<std::chrono::nanoseconds>(
             Clock::now().time_since_epoch()).count());
 }
+
 } // namespace
 
 SensorPipeline::SensorPipeline(std::size_t capacity)
-    : m_queue(capacity)
+  : SensorPipeline(capacity, getDefaultIntervals(), getDefaultIntervals())
+{
+}
+
+SensorPipeline::SensorPipeline(std::size_t capacity,
+                               const SensorPipelineIntervals& producerIntervals,
+                               const SensorPipelineIntervals& consumerIntervals)
+  : m_queue(capacity)
+  , m_producerIntervals(producerIntervals)
+  , m_consumerIntervals(consumerIntervals)
 {
 }
 
+
 SensorPipeline::~SensorPipeline()
 {
     stop();
@@ -64,10 +76,19 @@ void SensorPipeline::join()
     }
 }
 
+void SensorPipeline::status(std::ostream& os)
+{
+  os << "Producer enqueued: " << producer_enqueued << "\n"
+     << "         blocked:  " << producer_blocked  << "\n"
+     << "Consumer blocked:  " << consumer_blocked  << "\n"
+     << "         dequeued: " << consumer_dequeued << "\n";
+}
+
 void SensorPipeline::producerLoop()
 {
     PositionProducer producer;
 
+    // Loop getting measurements until done (stopped)
     while (m_running.load())
     {
         const weather::Position pos = producer.nextPosition();
@@ -81,12 +102,20 @@ void SensorPipeline::producerLoop()
 
         weather::AnyMeasurement msg(header, pos);
 
-        while (m_running.load() && !m_queue.try_enqueue(msg))
+        // busy loop until measurement successfully enqueued
+        while (m_running.load())
         {
-            std::this_thread::sleep_for(std::chrono::microseconds(50));
+          if (m_queue.try_enqueue(msg))
+          {
+              producer_enqueued++;
+              break;
+          } else {
+              producer_blocked++;
+              std::this_thread::sleep_for(m_producerIntervals.blockedWaitingInterval());
+          }
         }
 
-        std::this_thread::sleep_for(std::chrono::milliseconds(100));
+        std::this_thread::sleep_for(m_producerIntervals.pollingInterval());
     }
 }
 
@@ -107,9 +136,11 @@ void SensorPipeline::consumerLoop()
     {
         if (!m_queue.try_dequeue(msg))
         {
-            std::this_thread::sleep_for(std::chrono::microseconds(50));
+            consumer_blocked++;
+            std::this_thread::sleep_for(m_consumerIntervals.blockedWaitingInterval());
             continue;
         }
+        consumer_dequeued++;
 
         const weather::Position* pos = msg.try_get<weather::Position>();
         if (pos != nullptr)
@@ -122,13 +153,20 @@ void SensorPipeline::consumerLoop()
         }
     }
 
-    // Optional drain after stop (keeps output tidy)
-    while (m_queue.try_dequeue(msg))
+    // Drain after stop to ensure all measurements are used and
+    // pipeline is emptied)
+    while (true)
     {
-        const weather::Position* pos = msg.try_get<weather::Position>();
-        if (pos != nullptr)
+        if (m_queue.try_dequeue(msg))
         {
-            consumer.consume(*pos);
+            consumer_dequeued++;
+            const weather::Position* pos = msg.try_get<weather::Position>();
+            if (pos != nullptr)
+            {
+                consumer.consume(*pos);
+            }
+        } else {
+            break;
         }
     }
 }
diff --git a/Chapter7-SensorPipelines/src/main.cpp b/Chapter7-SensorPipelines/src/main.cpp
index 6f8efb8..cfd48cc 100644
--- a/Chapter7-SensorPipelines/src/main.cpp
+++ b/Chapter7-SensorPipelines/src/main.cpp
@@ -1,13 +1,19 @@
+#include <chrono>
+#include <iostream>
 #include <thread>
 
 #include "SensorPipeline.h"
+#include "BurstySensorPipelineIntervals.h"
+#include "DefaultSensorPipelineIntervals.h"
 
 using namespace weather;
 
 int main()
 {
     // "Capacity" is an initial sizing parameter for the SPSC queue.
-    SensorPipeline pipeline(/*capacity*/ 128);
+    SensorPipeline pipeline(128 /* capacity */,
+                            getBurstyIntervals() /* producer intervals */,
+                            getDefaultIntervals() /* consumer intervals */);
 
     pipeline.start();
 
@@ -17,6 +23,7 @@ int main()
     pipeline.stop();
     pipeline.join();
 
+    pipeline.status(std::cerr);
+
     return 0;
 }
-
diff --git a/Chapter8-SytemCompositionAndControl/CMakeLists.txt b/Chapter8-SystemCompositionAndControl/CMakeLists.txt
similarity index 58%
rename from Chapter8-SytemCompositionAndControl/CMakeLists.txt
rename to Chapter8-SystemCompositionAndControl/CMakeLists.txt
index c258c3f..4881203 100644
--- a/Chapter8-SytemCompositionAndControl/CMakeLists.txt
+++ b/Chapter8-SystemCompositionAndControl/CMakeLists.txt
@@ -1,21 +1,20 @@
 cmake_minimum_required(VERSION 3.16)
-project(chapter9_system_demo LANGUAGES CXX)
+project(chapter8_system_demo LANGUAGES CXX)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-add_executable(chapter9_demo
+add_executable(chapter8_demo
     src/main.cpp
     src/WeatherSystem.cpp
     src/WeatherSystemBuilder.cpp
-    src/Chapter9RunLoops.cpp
+    src/Chapter8RunLoops.cpp
     include/WeatherSystem.h
     include/WeatherSystemBuilder.h
-    include/Chapter9MeasurementFactory.h
-    include/Chapter9RunLoops.h
+    include/Chapter8RunLoops.h
 )
 
-target_include_directories(chapter9_demo PRIVATE
+target_include_directories(chapter8_demo PRIVATE
     include
     ../Common/include
     ../ThirdParty/readerwriterqueue
diff --git a/Chapter8-SytemCompositionAndControl/README.md b/Chapter8-SystemCompositionAndControl/README.md
similarity index 73%
rename from Chapter8-SytemCompositionAndControl/README.md
rename to Chapter8-SystemCompositionAndControl/README.md
index d574a23..3abbbd2 100644
--- a/Chapter8-SytemCompositionAndControl/README.md
+++ b/Chapter8-SystemCompositionAndControl/README.md
@@ -1,11 +1,11 @@
 // SPDX-License-Identifier: MIT
 // Copyright (c) 2025 Autumnal Software
 
-# Chapter 9 - System Controller (Snapshot)
+# Chapter 8 - System Composition And Control (Snapshot)
 
-This repository accompanies Chapter 9 of _Designing Deterministic Systems with Modern C++_.
+This repository accompanies Chapter 8 of _Designing Deterministic Systems with Modern C++_.
 
-This Chapter 9 demo is about system composition and control.
+This Chapter 8 demo is about system composition and control.
 
 - Uses `std::thread`
 - No Boost.Asio
@@ -18,7 +18,7 @@ This Chapter 9 demo is about system composition and control.
 This snapshot assumes the repository already provides:
 
 - `ThirdParty/readerwriterqueue`
-- `ThirdParty/boost_asio_1_36_0` (not used in Chapter 9, but present for later chapters)
+- `ThirdParty/boost_asio_1_36_0` (not used in Chapter 8, but present for later chapters)
 - `../Chapter7-ImprovedAnyMeasurement/include` containing:
   - `MeasurementTypes.h`
   - `AnyMeasurement.h`
diff --git a/Chapter8-SytemCompositionAndControl/include/BuildStatus.h b/Chapter8-SystemCompositionAndControl/include/BuildStatus.h
similarity index 100%
rename from Chapter8-SytemCompositionAndControl/include/BuildStatus.h
rename to Chapter8-SystemCompositionAndControl/include/BuildStatus.h
diff --git a/Chapter8-SytemCompositionAndControl/include/Chapter9RunLoops.h b/Chapter8-SystemCompositionAndControl/include/Chapter8RunLoops.h
similarity index 87%
rename from Chapter8-SytemCompositionAndControl/include/Chapter9RunLoops.h
rename to Chapter8-SystemCompositionAndControl/include/Chapter8RunLoops.h
index 9904efe..31e8ec1 100644
--- a/Chapter8-SytemCompositionAndControl/include/Chapter9RunLoops.h
+++ b/Chapter8-SystemCompositionAndControl/include/Chapter8RunLoops.h
@@ -9,7 +9,7 @@
 #include "LogEvent.h"
 #include "readerwriterqueue.h"
 
-struct Chapter9Stats
+struct Chapter8Stats
 {
     std::atomic<std::uint64_t> enqTempOk{0};
     std::atomic<std::uint64_t> enqPosOk{0};
@@ -27,10 +27,10 @@ struct Chapter9Stats
 
 
 
-class Chapter9RunLoops
+class Chapter8RunLoops
 {
 public:
-    Chapter9RunLoops(moodycamel::ReaderWriterQueue<weather::AnyMeasurement>& inQ,
+    Chapter8RunLoops(moodycamel::ReaderWriterQueue<weather::AnyMeasurement>& inQ,
                      moodycamel::ReaderWriterQueue<LogEvent>& logQ);
 
     void producer(const std::atomic<bool>& stop);
@@ -41,5 +41,5 @@ class Chapter9RunLoops
     moodycamel::ReaderWriterQueue<weather::AnyMeasurement>& m_inQ;
     moodycamel::ReaderWriterQueue<LogEvent>& m_logQ;
 
-    Chapter9Stats m_stats;
+    Chapter8Stats m_stats;
 };
diff --git a/Chapter8-SytemCompositionAndControl/include/LogEvent.h b/Chapter8-SystemCompositionAndControl/include/LogEvent.h
similarity index 100%
rename from Chapter8-SytemCompositionAndControl/include/LogEvent.h
rename to Chapter8-SystemCompositionAndControl/include/LogEvent.h
diff --git a/Chapter8-SytemCompositionAndControl/include/WeatherSystem.h b/Chapter8-SystemCompositionAndControl/include/WeatherSystem.h
similarity index 91%
rename from Chapter8-SytemCompositionAndControl/include/WeatherSystem.h
rename to Chapter8-SystemCompositionAndControl/include/WeatherSystem.h
index ddd12fe..8850f0a 100644
--- a/Chapter8-SytemCompositionAndControl/include/WeatherSystem.h
+++ b/Chapter8-SystemCompositionAndControl/include/WeatherSystem.h
@@ -12,7 +12,7 @@
 #include "LogEvent.h"
 #include "readerwriterqueue.h"
 
-class Chapter9RunLoops;
+class Chapter8RunLoops;
 
 class WeatherSystem
 {
@@ -35,13 +35,13 @@ class WeatherSystem
     moodycamel::ReaderWriterQueue<weather::AnyMeasurement>& inQueue() noexcept;
     moodycamel::ReaderWriterQueue<LogEvent>& logQueue() noexcept;
 
-    Chapter9RunLoops& runLoops() noexcept;
+    Chapter8RunLoops& runLoops() noexcept;
 
 private:
     moodycamel::ReaderWriterQueue<weather::AnyMeasurement> m_inQ;
     moodycamel::ReaderWriterQueue<LogEvent> m_logQ;
 
-    Chapter9RunLoops* m_runLoops;
+    Chapter8RunLoops* m_runLoops;
 
     std::array<std::function<void(const std::atomic<bool>&)>, ThreadCount> m_entries {};
     std::array<std::thread, ThreadCount> m_threads {};
diff --git a/Chapter8-SytemCompositionAndControl/include/WeatherSystemBuilder.h b/Chapter8-SystemCompositionAndControl/include/WeatherSystemBuilder.h
similarity index 100%
rename from Chapter8-SytemCompositionAndControl/include/WeatherSystemBuilder.h
rename to Chapter8-SystemCompositionAndControl/include/WeatherSystemBuilder.h
diff --git a/Chapter8-SytemCompositionAndControl/src/Chapter9RunLoops.cpp b/Chapter8-SystemCompositionAndControl/src/Chapter8RunLoops.cpp
similarity index 95%
rename from Chapter8-SytemCompositionAndControl/src/Chapter9RunLoops.cpp
rename to Chapter8-SystemCompositionAndControl/src/Chapter8RunLoops.cpp
index 7c5e745..8d3b18a 100644
--- a/Chapter8-SytemCompositionAndControl/src/Chapter9RunLoops.cpp
+++ b/Chapter8-SystemCompositionAndControl/src/Chapter8RunLoops.cpp
@@ -7,7 +7,7 @@
 #include <chrono>
 #include <thread>
 
-#include "Chapter9RunLoops.h"
+#include "Chapter8RunLoops.h"
 #include "MeasurementTypes.h"
 
 //
@@ -39,7 +39,7 @@ static void updateMax(std::atomic<std::uint64_t>& maxVal,
     }
 }
 
-Chapter9RunLoops::Chapter9RunLoops(
+Chapter8RunLoops::Chapter8RunLoops(
     moodycamel::ReaderWriterQueue<weather::AnyMeasurement>& inQ,
     moodycamel::ReaderWriterQueue<LogEvent>& logQ)
     : m_inQ(inQ)
@@ -47,7 +47,7 @@ Chapter9RunLoops::Chapter9RunLoops(
 {
 }
 
-void Chapter9RunLoops::producer(const std::atomic<bool>& stop)
+void Chapter8RunLoops::producer(const std::atomic<bool>& stop)
 {
     using namespace std::chrono;
 
@@ -112,7 +112,7 @@ void Chapter9RunLoops::producer(const std::atomic<bool>& stop)
     }
 }
 
-void Chapter9RunLoops::consumer(const std::atomic<bool>& stop)
+void Chapter8RunLoops::consumer(const std::atomic<bool>& stop)
 {
     using namespace std::chrono;
 
@@ -150,7 +150,7 @@ void Chapter9RunLoops::consumer(const std::atomic<bool>& stop)
                 updateMax(m_stats.latencyMaxNs, nowNs - rxNs);
             }
 
-            // No per-message logging in Chapter 9.
+            // No per-message logging in Chapter 8.
         }
         else
         {
@@ -160,7 +160,7 @@ void Chapter9RunLoops::consumer(const std::atomic<bool>& stop)
 }
 
 
-void Chapter9RunLoops::logger(const std::atomic<bool>& stop)
+void Chapter8RunLoops::logger(const std::atomic<bool>& stop)
 {
     using namespace std::chrono;
 
diff --git a/Chapter8-SytemCompositionAndControl/src/WeatherSystem.cpp b/Chapter8-SystemCompositionAndControl/src/WeatherSystem.cpp
similarity index 89%
rename from Chapter8-SytemCompositionAndControl/src/WeatherSystem.cpp
rename to Chapter8-SystemCompositionAndControl/src/WeatherSystem.cpp
index 185e804..3730858 100644
--- a/Chapter8-SytemCompositionAndControl/src/WeatherSystem.cpp
+++ b/Chapter8-SystemCompositionAndControl/src/WeatherSystem.cpp
@@ -2,12 +2,12 @@
 // Copyright (c) 2025 Autumnal Software
 
 #include "WeatherSystem.h"
-#include "Chapter9RunLoops.h"
+#include "Chapter8RunLoops.h"
 
 WeatherSystem::WeatherSystem()
     : m_inQ(256)
     , m_logQ(64)
-    , m_runLoops(new Chapter9RunLoops(m_inQ, m_logQ))
+    , m_runLoops(new Chapter8RunLoops(m_inQ, m_logQ))
 {
 }
 
@@ -59,7 +59,7 @@ moodycamel::ReaderWriterQueue<LogEvent>& WeatherSystem::logQueue() noexcept
     return m_logQ;
 }
 
-Chapter9RunLoops& WeatherSystem::runLoops() noexcept
+Chapter8RunLoops& WeatherSystem::runLoops() noexcept
 {
     return *m_runLoops;
 }
diff --git a/Chapter8-SytemCompositionAndControl/src/WeatherSystemBuilder.cpp b/Chapter8-SystemCompositionAndControl/src/WeatherSystemBuilder.cpp
similarity index 95%
rename from Chapter8-SytemCompositionAndControl/src/WeatherSystemBuilder.cpp
rename to Chapter8-SystemCompositionAndControl/src/WeatherSystemBuilder.cpp
index 56424f3..0463f28 100644
--- a/Chapter8-SytemCompositionAndControl/src/WeatherSystemBuilder.cpp
+++ b/Chapter8-SystemCompositionAndControl/src/WeatherSystemBuilder.cpp
@@ -2,7 +2,7 @@
 // Copyright (c) 2025 Autumnal Software
 
 #include "WeatherSystemBuilder.h"
-#include "Chapter9RunLoops.h"
+#include "Chapter8RunLoops.h"
 
 BuildStatus WeatherSystemBuilder::build(WeatherSystem& system) const
 {
diff --git a/Chapter8-SytemCompositionAndControl/src/main.cpp b/Chapter8-SystemCompositionAndControl/src/main.cpp
similarity index 90%
rename from Chapter8-SytemCompositionAndControl/src/main.cpp
rename to Chapter8-SystemCompositionAndControl/src/main.cpp
index 7b2c738..840369d 100644
--- a/Chapter8-SytemCompositionAndControl/src/main.cpp
+++ b/Chapter8-SystemCompositionAndControl/src/main.cpp
@@ -46,8 +46,12 @@ int main(int argc, char** argv)
         lock_memory(); // After construction, before execution
     }
 
+
+    const auto deviceRunLength{std::chrono::seconds(15)};
+
+
     system.start();
-    std::this_thread::sleep_for(std::chrono::seconds(5));
+    std::this_thread::sleep_for(deviceRunLength);
     system.stop();
     system.join();
 
diff --git a/Chapter8-SytemCompositionAndControl/include/Chapter9MeasurementFactory.h b/Chapter8-SytemCompositionAndControl/include/Chapter9MeasurementFactory.h
deleted file mode 100644
index 3fb4c8b..0000000
--- a/Chapter8-SytemCompositionAndControl/include/Chapter9MeasurementFactory.h
+++ /dev/null
@@ -1,21 +0,0 @@
-// SPDX-License-Identifier: MIT
-// Copyright (c) 2025 Autumnal Software
-
-#pragma once
-
-#include <chrono>
-#include <cstdint>
-
-#include "AnyMeasurement.h"
-#include "MeasurementTypes.h"
-
-namespace chapter9
-{
-    using Clock = std::chrono::steady_clock;
-
-    // Convert steady_clock time_point to a monotonic nanosecond tick count.
-    std::uint64_t to_ns(Clock::time_point t) noexcept;
-
-    weather::AnyMeasurement make_temperature(double seed, Clock::time_point eventTime, Clock::time_point rxTime);
-    weather::AnyMeasurement make_position(double seed, Clock::time_point eventTime, Clock::time_point rxTime);
-}
diff --git a/Chapter8-SytemCompositionAndControl/src/Chapter9MeasurementFactory.cpp b/Chapter8-SytemCompositionAndControl/src/Chapter9MeasurementFactory.cpp
deleted file mode 100644
index fb072be..0000000
--- a/Chapter8-SytemCompositionAndControl/src/Chapter9MeasurementFactory.cpp
+++ /dev/null
@@ -1,44 +0,0 @@
-// SPDX-License-Identifier: MIT
-// Copyright (c) 2025 Autumnal Software
-
-#include "Chapter9MeasurementFactory.h"
-
-namespace chapter9
-{
-    std::uint64_t to_ns(Clock::time_point t) noexcept
-    {
-        return static_cast<std::uint64_t>(
-            std::chrono::duration_cast<std::chrono::nanoseconds>(t.time_since_epoch()).count());
-    }
-
-    weather::AnyMeasurement make_temperature(double seed, Clock::time_point eventTime, Clock::time_point rxTime)
-    {
-        weather::MeasurementHeaderV1 h;
-        h.eventTime = to_ns(eventTime);
-        h.rxTime = to_ns(rxTime);
-        h.source = weather::SourceId::Unknown;
-        h.flags = 0;
-        // kind is set by AnyMeasurement via MeasurementKindOf<T>
-
-        weather::Temperature t;
-        t.value = 20.0 + seed;
-
-        return weather::AnyMeasurement(h, t);
-    }
-
-    weather::AnyMeasurement make_position(double seed, Clock::time_point eventTime, Clock::time_point rxTime)
-    {
-        weather::MeasurementHeaderV1 h;
-        h.eventTime = to_ns(eventTime);
-        h.rxTime = to_ns(rxTime);
-        h.source = weather::SourceId::Unknown;
-        h.flags = 0;
-
-        weather::Position p;
-        p.lat = 43.0 + seed * 0.0001;
-        p.lon = -77.0 + seed * 0.0001;
-        p.alt = 150.0;
-
-        return weather::AnyMeasurement(h, p);
-    }
-}
diff --git a/Common/CMakeLists.txt b/Common/CMakeLists.txt
index fae86d6..0c4022b 100644
--- a/Common/CMakeLists.txt
+++ b/Common/CMakeLists.txt
@@ -10,6 +10,7 @@ add_library(Common STATIC
     # Public headers (explicit)
     include/ImmutableByteView.h
     include/MutableByteView.h
+    include/Counters.h
 
     include/Status.h
 
diff --git a/Common/include/Counters.h b/Common/include/Counters.h
new file mode 100644
index 0000000..bca08e5
--- /dev/null
+++ b/Common/include/Counters.h
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <atomic>
+#include <new>
+
+
+// A counter that is isolated on a cache line.  Thread-safe plus isolated on a single cache line
+// so incrementing it won't have interference penalties.
+struct Counter
+{
+  void incr() { ++value; }
+  void operator++() { incr(); }
+  void operator++(int) { incr(); }
+
+  operator unsigned long() const { return value.load(); }
+
+private:
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Winterference-size"
+  static constexpr auto cache_line_size = std::hardware_destructive_interference_size;
+#pragma GCC diagnostic pop
+  alignas(cache_line_size) std::atomic<unsigned long> value {0};
+  char _padding_[cache_line_size - sizeof(long)];
+};
diff --git a/SetupChapter/jitter_test.cpp b/SetupChapter/jitter_test.cpp
index f8a3587..da980d2 100644
--- a/SetupChapter/jitter_test.cpp
+++ b/SetupChapter/jitter_test.cpp
@@ -80,9 +80,8 @@ int main(int argc, char* argv[])
     const long double avg_abs = sum_abs / static_cast<long double>(abs_jitter.size());
 
     std::sort(abs_jitter.begin(), abs_jitter.end());
-    const std::size_t idx_99 = static_cast<std::size_t>(
-        (abs_jitter.size() - 1) * 0.99
-    );
+    const std::size_t idx_99 = static_cast<std::size_t>(static_cast<float>(abs_jitter.size() - 1) * 0.99);
+
     const long long p99_abs = abs_jitter[idx_99];
 
     std::cout << "Jitter statistics (nanoseconds)\n";
@@ -94,4 +93,3 @@ int main(int argc, char* argv[])
 
     return 0;
 }
-
diff --git a/global b/global
deleted file mode 100644
index e69de29..0000000