diff -u -r freecivold3/server/citytools.c freecivold2/server/citytools.c
--- freecivold3/server/citytools.c	Wed Feb 23 22:58:09 2000
+++ freecivold2/server/citytools.c	Wed Feb 23 23:07:14 2000
@@ -521,11 +521,11 @@
 {
   int tax_bonus = 100;
   if (city_got_building(pcity, B_MARKETPLACE)) {
-    tax_bonus+=50;
+    tax_bonus*=50;
     if (city_got_building(pcity, B_BANK)) {
-      tax_bonus+=50;
+      tax_bonus*=50;
       if (city_got_building(pcity, B_STOCK)) 
-	tax_bonus+=50;
+	tax_bonus*=50;
     }
   }
   pcity->tax_bonus = tax_bonus;
@@ -544,17 +544,17 @@
 {
   int science_bonus = 100;
   if (city_got_building(pcity, B_LIBRARY)) {
-    science_bonus+=50;
+    science_bonus*=1.5;
     if (city_got_building(pcity, B_UNIVERSITY)) {
-      science_bonus+=50;
+      science_bonus*=1.5;
     }
     if (city_got_effect(pcity, B_RESEARCH))
-      science_bonus+=50;
+      science_bonus*=1.5;
   }
   if (city_affected_by_wonder(pcity, B_COPERNICUS)) 
-    science_bonus+=50;
+    science_bonus*=1.5;
   if (city_affected_by_wonder(pcity, B_ISAAC))
-    science_bonus+=100;
+    science_bonus*=2;
   pcity->science_bonus = science_bonus;
   return science_bonus;
 }