Mr。 Peterkin thought that would not be necessary。 He had seen signs on doors of 〃Night Doctor；〃 and certainly it would be as convenient to have a sign of 〃Not a Night Doctor。〃
Solomon John thought he might write his advice to those of his patients who were dangerously ill； from whom there was danger of infection。 And then Elizabeth Eliza agreed that his prescriptions would probably be so satisfactory that they would keep his patients well；…not too well to do without a doctor； but needing his recipes。
Agamemnon was delayed； however； in his choice of a profession； by a desire he had to become a famous inventor。 If he could only invent something important； and get out a patent； he would make himself known all over the country。 If he could get out a patent he would be set up for life； or at least as long as the patent lasted； and it would be well to be sure to arrange it to last through his natural life。
Indeed； he had gone so far as to make his invention。 It had been suggested by their trouble with a key； in their late moving to their new house。 He had studied the matter over a great deal。 He looked it up in the Encyclop？dia； and had spent a day or two in the Public Library； in reading about Chubb's Lock and other patent locks。
But his plan was more simple。 It was this： that all keys should be made alike ！
He wondered it had not been thought of before； but so it was； Solomon John said； with all inventions； with Christopher Columbus； and everybody。 Nobody knew the invention till it was invented； and then it looked very simple。 With Agamemnon's plan you need have but one key； that should fit everything！ It should be a medium…sized key； not too large to carry。 It ought to answer for a house door； but you might open a portmanteau with it。 How much less danger there would be of losing one's keys if there were only one to lose！
Mrs。 Peterkin thought it would be inconvenient if their father were out； and she wanted to open the jam…closet for the little boys。 But Agamemnon explained that he did not mean there should be but one key in the family； or in a town；…you might have as many as you pleased； only they should all be alike。
Elizabeth Eliza felt it would be a great convenience；…they could keep the front door always locked； yet she could open it with the key of her upper drawer； that she was sure to have with her。 And Mrs。 Peterkin felt it might be a convenience if they had one on each story； so that they need not go up and down for it。
Mr。 Peterkin studied all the papers and advertisements； to decide about the lawyer whom they should consult； and at last； one morning； they went into town to visit a patent…agent。
Elizabeth Eliza took the occasion to make a call upon the lady from Philadelphia； but she came back hurriedly to her mother。
〃I have had a delightful call；〃 she said； 〃but…perhaps I was wrong…I could not help； in conversation； speaking of Agamemnon's proposed patent。 I ought not to have mentioned it； as such things are kept profound secrets； they say women always do tell things； I suppose that is the reason。〃
〃But where is the harm？ 〃 asked Mrs。 Peterkin。 〃 I'm sure you can trust the lady from Philadelphia。〃
Elizabeth Eliza then explained that the lady from Philadelphia had questioned the plan a little when it was told her； and had suggested that 〃 if everybody had the same key there would be no particular use in a lock。〃
〃Did you explain to her；〃 said Mrs。 Peterkin； 〃that we were not all to have the same keys？ 〃
〃I couldn't quite understand her；〃 said Elizabeth Eliza； 〃but she seemed to think that burglars and other people might come in if the keys were the same。〃
〃Agamemnon would not sell his patent to burglars！〃 said Mrs。 Peterkin； indignantly。
〃But about other people；〃 said Elizabeth Eliza； 〃there is my upper drawer； the little boys might open it at Christmas…time；…and their presents in it！〃
〃And I am not sure that I could trust Amanda；〃 said Mrs。 Peterkin； considering。
Both she and Elizabeth Eliza felt that Mr。 Peterkin ought to know what the lady from Philadelphia had suggested。 Elizabeth Eliza then proposed going into town； but it would take so long she might not reach them in time。 A telegram would be better； and she ventured to suggest using the Telegraph Alarm。
For； on moving into their new house； they had discovered it was provided with all the modern improvements。 This had been a disappointment to Mrs。 Peterkin； for she was afraid of them； since their experience the last winter； when their water…pipes were frozen up。 She had been originally attracted to the house by an old pump at the side； which had led her to believe there were no modern improvements。 It had pleased the little boys； too。 They liked to pump the handle up and down； and agreed to pump all the water needed； and bring it into the house。
There was an old well； with a picturesque well…sweep； in a corner by the barn。
Mrs。 Peterkin was frightened by this at first。 She was afraid the little boys would be falling in every day。 And they showed great fondness for pulling the bucket up and down。 It proved； however； that the well was dry。 There was no water in it； so she had some moss thrown down； and an old feather…bed； for safety； and the old well was a favorite place of amusement。
The house； it had proved； was well furnished with bath…rooms； and 〃set…waters〃
everywhere。 Water…pipes and gas…pipes all over the house； and a hack…； telegraph…； and fire…alarm； with a little knob for each。
Mrs。 Peterkin was very anxious。 She feared the little boys would be summoning somebody all the time； and it was decided to conceal from them the use of the knobs； and the card of directions at the side was destroyed。 Agamemnon had made one of his first inventions to help this。 He had arranged a number of similar knobs to be put in rows in different parts of the house； to appear as if they were intended for ornament； and had added some to the original knobs。 Mrs。
Peterkin felt more secure； and Agamemnon thought of taking out a patent for this invention。
It was； therefore； with some doubt that Elizabeth Eliza proposed sending a telegram to her father。 Mrs。 Peterkin； however； was pleased with the idea。
Solomon John was out； and the little boys were at school； and she herself would touch the knob； while Elizabeth Eliza should write the telegram。
〃I think it is the fourth knob from the beginning；〃 she said； looking at one of the rows of knobs。
Elizabeth Eliza was sure of this。 Agamemnon； she believed； had put three extra knobs at each end。
〃But which is the end； and which is the beginning； …the top or the bottom？〃 Mrs。
Peterkin asked hopelessly。
Still she bravely selected a knob； and Elizabeth Eliza hastened with her to look out for the messenger。 How soon should they see the telegraph boy？
They seemed to have scarcely reached the window； when a terrible noise was heard； and down the shady street the white horses of the fire…brigade were seen rushing at a fatal speed！
It was a terrific moment！
〃I have touched the fire…alarm；〃 Mrs。 Peterkin exclaimed。
Both rushed to open the front door in agony。 By this time the fire…engines were approaching。
〃Do not be alarmed；〃 said the chief engineer； 〃the furniture shall be carefully covered； and we will move all that is necessary。〃
〃Move again！〃 exclaimed Mrs。 Peterkin； in agony。
Elizabeth Eliza strove to explain that she was only sending a telegram to her father； who was in Boston。
〃It is not important；〃 said the head engineer； 〃the fire will all be out before it could reach him。〃
And he ran upstairs； for the engines were beginning to play upon the roof。
Mrs。 Peterkin rushed to the knobs again hurriedly； there was more necessity for summoning Mr。 Peterkin home。
〃Write a telegram to your father；〃 she said to Elizabeth Eliza； 〃to 'come home directly。'〃
〃That will take but three words；〃 said Elizabeth Eliza； with presence of mind； 〃and we need ten。 I was just trying to make them out。〃
〃What has come now？〃 exclaimed Mrs。 Peterkin； and they hurried again to the window； to see a row of carriages coming down the street。
〃I must have touched the carriage…knob；〃 cried Mrs。 Peterkin； 〃and I pushed it half…a…dozen times I felt so anxious！〃
Six hacks stood before the door。 All the village boys were assembling。 Even their own little boys had returned from school； and were showing the firemen the way to the well。
Again Mrs。 Peterkin rushed to the knobs； and a fearful sound arose。 She had touched the burglar…alarm ！
The former owner of the house； who had a great fear of burglars； had invented a machine of his own； which he had connected with a knob。 A wire attached to the knob moved a spring that could put in motion a number of watchmen's rattles； hidden under the eaves of the piazza。
All these were now set a…going； and their terrible din roused those of the neighborhood who had not before assembled around the house。 At this moment Elizabeth Eliza met the chief engineer。
〃You need not send for more help；〃 he said； 〃we have all the engines in town here； and have stirred up all the towns in the neighborhood； there's no use in spr