diff --git a/Stack/History/Event.hpp b/Stack/History/Event.hpp
index e47eaf2eca14f81c9f91a486e62516d3911f7dd1..c89f8064eb8e4a527384ba87c8aee9c3601546f5 100644
--- a/Stack/History/Event.hpp
+++ b/Stack/History/Event.hpp
@@ -42,6 +42,9 @@ namespace corsika::history {
 
     template <typename TStackIterator>
     TStackIterator projectile(TStackIterator begin) {
+      // MR: This is dangerous. You can pass any iterator though it must
+      // be stack.begin() to yield the correct projectile
+
       return begin + projectileIndex_;
     }
 
diff --git a/Stack/History/HistoryObservationPlane.hpp b/Stack/History/HistoryObservationPlane.hpp
index 8c2d5700daa63cce61d9f88705047f6aa2cf663e..a603963dba8c6ee746a0ddff1630f1cae6ff8cc9 100644
--- a/Stack/History/HistoryObservationPlane.hpp
+++ b/Stack/History/HistoryObservationPlane.hpp
@@ -21,7 +21,7 @@
 namespace corsika::history {
   namespace detail {
     auto hist_factory() {
-      auto h = boost::histogram::make_histogram(
+      /*auto h = boost::histogram::make_histogram(
           boost::histogram::axis::regular<double, boost::histogram::axis::transform::log>{
               130, 1e8, 1e21, "muon energy/eV"},
           boost::histogram::axis::integer<int, boost::histogram::use_default,
@@ -30,7 +30,12 @@ namespace corsika::history {
           boost::histogram::axis::regular<double, boost::histogram::axis::transform::log>{
               130, 1e8, 1e21, "hadronic energy/eV"},
           boost::histogram::axis::category<int, boost::histogram::use_default,
-                                           boost::histogram::axis::option::growth_t>{});
+                                           boost::histogram::axis::option::growth_t>{});*/
+
+      auto h = boost::histogram::make_histogram(
+          boost::histogram::axis::integer<int, boost::histogram::use_default,
+                                          boost::histogram::axis::option::growth_t>{
+              0, 10, "hadronic generation"});
       return h;
     }
   } // namespace detail
@@ -38,9 +43,9 @@ namespace corsika::history {
   class HistoryObservationPlane
       : public corsika::process::ContinuousProcess<HistoryObservationPlane> {
   public:
-    HistoryObservationPlane(geometry::Plane const&, bool = true);
+    HistoryObservationPlane(setup::Stack const&, geometry::Plane const&, bool = true);
 
-    void save(std::string const&);
+    //~ void save(std::string const&);
 
     corsika::units::si::LengthType MaxStepLength(
         corsika::setup::Stack::ParticleType const&,
@@ -53,6 +58,7 @@ namespace corsika::history {
   private:
     void fillHistoryHistogram(setup::Stack::ParticleType const&);
 
+    setup::Stack const& stack_;
     geometry::Plane const plane_;
     bool const deleteOnHit_;